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PSGA-101A User Manual

1. Laser output power in the External Laser Setup box Figure 26 The laser setup screen can also be accessed from the measurement window by clicking the Laser Setup button 2 After the laser setup is finished click OK to proceed to the measurement interface Figure 27 Click Start to start the measurement Select PDL from the pull down menu in the Graph box The real time wavelength dependence of the PDL will be shown on the lower graph After the measurement is finished use the pull down menus in the Numerical Values box at the bottom of the screen to display the average RMS standard deviation maximum or minimum value of the measured PDL PMD Jones Matrix Method 1 219 Manual Mode Tune laser wavelength nm to Wavelength nm Figure 27 PDL Measurement interface Once a measurement is completed the data can be saved by clicking the Save button The user will be prompted to input a file name and location for the saved data As previously noted the saved file includes DGD SOPMD PDL PSP Q absolute value of the parallel component of SOPMD Q absolute value of the perpendicular component of SOPMD and phase change vs wavelength Previously saved PDL data can also be recalled from this screen by clicking the Load button Once the user chooses the desired file the data will be displayed graphically on screen Document GP UM PSGA 101A 12 Page 42 of 86 6 3 Pol
2. MEA CHN STP Returns the step size nn of channels po Externalaser S O single wavelength operation MEA WAL UPR Returns the end wavelength nm fff ff MEA WAL STP Returns the wavelength step size nm ffff ff Document GP UM PSGA 101A 12 Page 80 of 86 9 8 Internal tunable laser commands TLS REG hhhhhh Query the TLS register Returns the status of hhhhhh is the register datal and data2 register hh hh hh hh For example to determine the status of register Refer to OIF ITLA 0x32 when datal is 0x00 and data2 is 0x00 the MSA for the meaning correct command is TLS REG 320000 of the data TLS CHN nn Sets the channel of the laser source nn 0 88 E00 OK EO1 undefined command E06 parameter out of range Returns the current channel number This CHN 12 command is available for sweep mode E0O1 undefined command TLS FRQ Returns the current frequency of laser source Cid TLS WAV Returns the current wavelength of laser source Cd Switch the laser source on or off oy 0 laser off 1 laser on TLS STA Queries the laser state STA O laser off 0 laser off STA 1 laser on 1 laser on STA 2 laser not 2 laser not available available TLS SWP MOD n Sets the sweep mode 0 manual mode 1 auto mode TLS SWP MOD Query the current operation mode MOD 0 1 TLS SWP CYC nnn Sets the number of scan cycles to be executed Range 1 lt nnn lt 999 if nnn gt 999 or nnn
3. 6 9 slow axis a Input Polarization Figure 28 A representation of linearly polarized light misaligned by an angle 0 from the slow axis of a PM fiber The misalignment angle is difficult to measure directly as it depends on the determination of the orientation of the fiber s slow axis Variations in the input wavelength or in the fiber length due to temperature changes or mechanical stress change the relative phase delay between the two orthogonal polarization components causing the state of polarization of the output light to rotate along a circle on the Poincar sphere The rotation axis of the circle is defined by the optical slow axis of the PM fiber and the Document GP UM PSGA 101A 12 Page 43 of 86 radius of the circle by the misalignment of the light to the slow axis as shown in Figure 29 Figure 29 Poincar Sphere illustration of polarization state rotation of output light from a PM fiber due to thermal or mechanical stress The polarization extinction ratio then can be calculated directly from the size of the circle so sin 2 z ate PER 10log 10 log 2 Sieg a 6 10 a OS eon Ea 1 V1 R For complete confinement in one mode R 0 the circle collapses to a point corresponding to PER At the other extreme if the light is evenly distributed between the two orthogonal polarization modes R 1 the circle becomes a circumference of the sphere corresponding to PER 0
4. IDN GP PSGA101 192 168 0 5 TLS CHN g9 192 168 0 5 IDN GP PSGA101 192 168 0 5 PSA MTD MTD 1 Bowe Left Up Clear ZIn ZOut PER 3 30 GB Azimuth 65 79 Draw Option 2 start PwPolawise EE 9 35 AM Figure 59 Communication Interface Users can use any programming language that supports the TCP IP for Ethernet or IEEE 488 2 for GPIB communication protocols to send commands to the PSGA 101A Document GP UM PSGA 101A 12 Page 74 of 86 Note For commands that include a parameter such as a wavelength there should be exactly one space between the command body and the parameter For example PSG WAV 1500 00 Omitting the space or adding multiple spaces may result in an error message 9 3 PSG GPIB Ethernet Commands Setup Commands Control Command Error Response PSG STA lt state gt Sets the PSG output polarization state E00 E01 E02 lt state gt RHC LHC LHP LVP 45 45 SCAN Eg PSG STA 45 set PSG output state to 45 PSG DWL ff ff Sets PSG dwell time all values in sec E00 E01 E02 Unused digits do not need to be filled E06 Example PSG DWL 1 set dwell time to 1 sec Range gt 0 1s PSG WAY ffff ff Sets PSG wavelength all values in nm E00 E01 E02 Unused digits do not need to be filled E06 Example PSG WAV 1500 00 Range 1440nm 1620nm PSG ADPOW Toggles 90 polarization rotator setting Used to E00 E01 E02 increase PSG output power when initial inpu
5. In the PSGA system the output light is directly coupled into the PSA through a free space interface so the rotation axis of the circle is on the plane of the equator of the Poincar sphere and the angle is the angle between the slow axis and the reference plate of the PSA Because the key slot of the PSA adapter is aligned perpendicular to the reference plate the angle 90 represents the angle between the slow axis of the PM fiber and the connector key For example Y 90 means that the slow axis of the PM fiber is vertical and aligned to the alignment key direction Y 0 means that the slow axis of the PM fiber is horizontal and perpendicular to the alignment key direction In practical measurement the center of the circle generally deviates from the plane of the equator This deviation is caused by stress and or other defects at the connector Generally greater deviation from the equator indicates higher stress Document GP UM PSGA 101A 12 Page 44 of 86 6 3 2 PER Measurement Setup The PER measurement setup is shown in Figure 30 If using the internal tunable laser make sure that the laser key is turned to the on position before beginning measurement PM fiber iii Polarization Controller Figure 30 Measurement setup for PER measurement of PM fiber Note The manual polarization controller is useful for characterizing lengths of PM fiber but is not necessary for all DUTs 6 3 3 PER Measurement Procedur
6. Two way A round trip scan starting at the designated start wavelength proceeding to the end wavelength and then scanning back to the start wavelength This process 1s repeated the number of times set in the Set Cycle box Auto Cycle Mode Wavelength sweeps continuously according to the parameters set in the Cycle parameter box Star Starts channel wavelength sweep Bo Stops channel wavelength sweep In manual scan mode tunes the channel wavelength to the next channel in the sequence dictated by the scan parameters set in the Cycle parameter box Get Info Displays the current scan parameters Message Box Shows laser command response codes last line in window E00 OK EO1 command error E13 parameter setting error the start and end channel H E pS e settings are not compatible with the step size E14 command conflict For example Start used during a scan E15 TLA is not ready for output Command should be re sent The output wavelengths of the internal tunable laser source match the 50GHz ITU grid Corresponding channel numbers and wavelengths are listed in Table 4 Document GP UM PSGA 101A 12 Page 69 of 86 Table 4 Tunable laser output channels and corresponding wavelengths Channel Wavelength Channel Wavelength Channel Wavelength nm nm nm a Pp 2 152916 7 68 1555 34 9 1531 90 89 1563 86 60 1552 12 a Document GP U
7. e The PSGA 101A is not user serviceable It should be serviced only by factory authorized personnel The front panel of the PSGA 101A contains the main power switch Power laser key Light liquid crystal display LCD push button control pads keyboard connector two USB connectors and four optical connectors as shown in Figure One of the USB connectors is generally used for mouse control the other can be used for flash memory A flip top LCD graphic display is located on top of the main body of the PSGA I101A Front panel description LCD display displays data and operation mode information Power main electrical power on off switch Light key enables disables control of the internal tunable laser Laser OUT output connector for internal tunable laser PSG IN PSG light input connector for connecting external or internal light source to the PSG PSG OUT PSG output connector PSA IN PSA input connector Keypad push buttons for measurement status control see Section 7 Keyboard connector port to connect a keyboard to the PSGA I01A USB two USB ports for mouse control and flash memory Document GP UM PSGA 101A 12 Page 10 of 86 The AC power plug fuse Ethernet and GPIB interface connectors external VGA connector two BNC connectors two cooling fans and the chassis ground connector are mounted on the rear panel as shown in Figure 3 GENERAL PHOTONICS CORP CHINO CA USA Figure 3 PSGA 101A rear pa
8. 0 120 Sa 0 003 Jae 5 12 PM Figure 7 PSA and PSG status boxes When the PSA is enabled the PSA status box shows the current values of the selected polarization parameters in the pull down menus S1 S2 S3 etc as well as the power in dBm and degree of polarization DOP of the light input to the PSA Note If the input power to the PSA is out of range measurements cannot be performed properly The PSA will indicate power out of range with a Power High or Power Low indication in the power box See section 15 3 for more details The PSG status box shows the current selected wavelength and output polarization state of the PSG See section 15 2 for more details Section 5 Polarization State Generation and Analysis 5 1 Polarization Parameters The following are polarization parameters used throughout this manual e Si S2 and Sz The normalized Stokes parameters of the polarization state The value of 4S 55 S is equal to 1 So optical input power unit dBm Azimuth Azimuth angle y of polarization ellipse unit degrees Ellipticity Ellipticity angle y of polarization ellipse unit degrees DOP Degree of polarization usually given as a percentage of input light DLP Degree of linearity usually given as a percentage of polarized input light DCP Degree of circularity usually given as a percentage of polarized input light Document GP UM PSGA 101A 12 Page 16 of 86 Graphical representations of po
9. A L da If the chromatic dispersion equation of the fiber is 2 2 2 n 1 zi SoA ae 6 16 ee then the beat length can be calculated from Z EDIE 6 17 L 4 4 4 TN yar BH et Bvt n A Q A 0 A C Document GP UM PSGA 101A 12 Page 54 of 86 For PM fiber DGD 1319 DGD 1550 so the beat length at 1310 nm can be estimated from a measured value according to the following formula 1310 Lg1310 4s 6 l 8 Where Lp is the measured beat length at wavelength 6 7 2 Beat Length Measurement Procedure e Select Beat Length Measurement from the Measurements menu at the top of the main interface screen Figure 40 Display Help PME FOL Mueller Matrix PRIDJPDL Jones Matrix PRIDPDLi Jones Matrix Fast Mode PRIOVPoincare Sphere Analysis PMD Wavelength Scanning POL Jones Matrix Single WL POL Mueller Matrix Single WL Mueller Matrix Measurement Beat Length Measurement PSG PER Measurement Longterm Measurement Angle Measurement Figure 40 Beat Length Measurement selection e After the measurement method is selected a tunable laser setup dialog window Figure 19 pops up Select Laser Type from the pull down menu Standard options are internal tunable laser and Agilent tunable laser Other tunable laser sources can be added by customer request e After the laser type and scanning wavelength range are set up click the OK button to save the laser setup and bring up the beat length meas
10. DUT box in the lower half of the screen Figure 37 The corresponding polarization dependent loss PDL and insertion loss IL are also calculated and displayed Mueller Matrix of DUT Reference 1 000 0 000 o 002 Moo Ref 0 012 fo 175 fo 161 0 f 280 i 0 012 0 746 0 631 0 031 0 637 0 754 D DUT 1 000 0 000 0 000 MOO DUT 0 000 1 000 0 000 fi 001 o o00 0 001 1 001 0 000 PDL 0 002 dB IL 0 004 dB Document GP UM PSGA 101A 12 Page 50 of 86 Figure 37 Measured Mueller matrix The M00 DUT is the first element of the Mueller matrix in the first column and the first row The Mueller matrix is divided by M00 and the results are shown next to M00 DUT 6 5 Long Term Measurement The long term measurement function allows the user to measure record and display the time dependence of the SOP of input light Long Term Measurement Procedure Select Long Term Measurement from the Measurements menu at the top of the main interface screen Figure 38a A long term measurement interface box will appear at the bottom right corner of the main screen Figure 38b in place of the PSG control box Display Help PRIDVPDL Mueller Matrix PRIDVPDL i Jones Matrix PME FOL Jones Matrix Fast Mode PMID Poincare Sphere Analysis PME Wavelength Scanning Longterm Cation Free Run S00 Periods 3 ji PDL Jones Matrix Single YL PDL Mueller Matrix Single WL Mueller
11. PSGA plots out Stokes parameters S1 S2 and S vs wavelength as the measurement proceeds When the measurement is finished it displays the PMD values calculated from the extrema in each graph in the PMD Data box at the top right of the screen Once a measurement is completed the data can be saved by clicking the Save button The user will be prompted to input a file name and location for the saved data The file includes S1 S2 and S3 vs wavelength as well as the PMD values calculated from each Stokes parameter curve Previously saved wavelength scanning data can be recalled from this screen by clicking the Load button Once the user chooses the desired file the data will be displayed on the screen Document GP UM PSGA 101A 12 Page 36 of 86 6 2 Polarization Dependent Loss PDL Measurement The phenomenon of polarization dependent loss PDL describes the insertion loss variation gain variation or coupling variation of an optical component over all possible input signal polarization states Polarization dependent loss is defined as the maximum insertion loss IL expressed in dB minus the minimum IL expressed in dB due to input polarization variation The PSGA 101A measures polarization dependent loss PDL or gain PDG using either the Mueller matrix method or the Jones matrix method 6 2 1 PDL Measurement Principle At each wavelength specified in the measurement setup the Mueller matrix Section 6 4 or
12. Powie wy comu ae Select Angle Measurement from the Measurements menu at the top of the main interface screen Figure 39a An Angle Measurement interface will appear at the bottom right corner of the screen replacing the PSG control box Figure 39b Fie Setup Measurements Display Help PSA L DISABLEPSA s1 v 0 6409 s2 x 0 7219 s3 x 0 2610 Power 4 062dBm 60 DOP 29 80 Angle Measurement Hl Restle y ms ee oe Berle k 0 640 fo 722 0 261 inge eA a elle p Left Right Up Down Home clear ZIn zout Draw Option psa PSG Paint Trace a Measurement menu b Sphere display with angle interface c Figure 39 Angle Measurement selection To mark the current SOP point on the Poincar sphere select a marker name from the pull down menu in the dialog box Figure 39c then click Set to mark that point A labeled marker will appear on the sphere and the Stokes parameters of the point will be displayed in the S1 S2 and S3 boxes in the Angle Measurement area Up to 10 separate points can be marked Selecting the marker name of a particular marked point from the pull down menu in Figure 39c will recall the Stokes parameters of that point To calculate the angle between two marked points select the marker names of the points between which the angle is to be calculated from the pull down menus in the Angle line A and B in the example
13. UM PSGA 101A 12 Page 56 of 86 Section 7 Front Panel Control In addition to the user friendly graphic display control and measurement interface the PSGA 101A also provides control access through the front panel LCD and function keys This feature can simplify measurements for particular applications or environments Figure 42 shows the front panel layout of the PSGA 101A The ten major function keys are located under the blue LCD screen LIGHT Lamanai ME ay PSG A 101 4 Polavvise POLARGATION MEASUREMENT SYSTEM General Photonics 2 PSGA V1 0 e POWER USB PSG PSA PER PMD PDL LASER PSG PSA PRINT STORE TLS DISPLAY KEYBOARD Pami PUS mM raae OUT IN OUT IN Figure 42 Front panel layout of the PSGA 101A When the PSGA 101A is first turned on the flip up LCD graphic display is automatically enabled After initialization it shows the interface screen pictured in Figure 4 The front panel LCD display shows General Photonics PSGA V1 0 Figure 43 Front panel LCD startup screen As long as the flip up LCD graphic display 1s enabled the front panel LCD displays the startup screen shown in Figure 43 and most of the front panel function keys are disabled Only the PRINT and DISPLAY keys will respond The DISPLAY key toggles the flip up LCD graphic display on and off When it 1s off the PSGA s front panel control is enabled The PSGA accepts input from the front panel keys and displays results t
14. arrow keys A V to select Single Wavelength setup or Wavelength Scan setup Press to select the highlighted option e If Single Wavelength is selected the display proceeds to the wavelength selection screen Figure 51B Use the arrow keys to set the wavelength and 4 to execute the setting e If Wavelength Scan is selected the display proceeds to the first scan setup screen Figure 51C Use the arrow keys to set the start wavelength scanning step step number and dwell time for PMD measurement Press to execute the setting Document GP UM PSGA 101A 12 Page 66 of 86 7 8 Measurement or setup data storage The Store key is used to save current settings or measurement data to a file When the key is pressed the file storage menu is displayed Figure 52 1 Type PSG 2 FileName xx 3 Save Figure 52 Data storage interface e When the file storage menu first appears option 1 is highlighted Use the arrow keys to select 1 2 or 3 e If 1 is selected press to access the file type options Use the up and down arrow keys A V to scroll through file type options PSG PDL PMD and TLS e Use the left and right arrow keys lt gt to move to option 2 and to select it then use the up and down arrow keys A to change the file number xx range is 1 99 Press J to accept the file number and return to menu option selection the cursor will move to the 2 before FileName on the menu
15. cord fiber to avoid wear on the internal connector Hole for alignment pin Remove screws Adapter base Ferrule end Front flange do not remove Figure 2 Diagram of universal connector interface External fiber connectors should be cleaned using industry standard cleaning methods before connection to the PSGA I01A If this procedure is followed before each connection the instrument s internal connector ferrules should not need regular cleaning However high insertion loss or measurement instability that does not improve after cleaning the external connectors may indicate that the instrument s internal connector ferrules require cleaning Note The output power of the PSGA 101A s internal tunable laser is fixed and may be as high as 13 14 dBm To ensure that the light input to the PSA is within the specified dynamic range for accurate measurements 40 to 2 dBm a 10 dB optical attenuator is supplied as an accessory with the PSGA 101A The attenuator should be connected between the laser output and the PSG input Document GP UM PSGA 101A 12 Page 9 of 86 3 2 Electrical Features The PSGA 101A system uses the standard wall electricity supply 100 240V 50 60Hz Due to high voltage the following safety precautions must be exercised during operation e The ground pin on the power supply cord must be connected to earth ground of the wall receptacle e Never touch the boards inside the package without proper insulation
16. lt 1 the number of cycles will be defined to be infinite INF and the laser will continue scanning until manually stopped Sample commands TLS SWP CYC nnn TLS SWP CYC INF TLS SWP CYC Returns the number of scan cycles set CYC O cycle is infinite TLS SWP DWE nnnn Sets the dwell time per step for auto sweep mode Can only be used in auto mode Range for nnnn is 20 3600 ms Sample command TLS SWP DWE 100 TLS SWP DWE Returns the dwell time per step auto sweep mode TLS SWP REP n Sets the repeat mode N 0 orl 0 One way Every sweep cycle starts at the start wavelength and ends at the end wavelength 1 Round trip Each sweep cycle starts at the start wavelength scans to the end wavelength then scans back to the start wavelength Document GP UM PSGA 101A 12 Page 81 of 86 TLS SWP REP Returns the current repeat mode Sets the start channel for a sweep nn 0 88 Sample commands TLS SWP BGN nn TLS SWP BGN 0 TLS SWP BGN 88 O one way 1 round trip TLS SWP BGN Returns the currently set sweep start channel ft TLS SWP END nn Sets the end channel for a sweep nn 0 88 nee TLS SWP END Returns the currently set sweep end channel ee TLS SWP STE nn Sets the step size of channels nn 1 88 TLS SWP STE Returns the step size of channels fe TLS SWP STA n Stops starts pauses or continues a paused channel sweep Options for n 0 stop I
17. method file includes S1 S2 and S3 vs wavelength as well as the PMD values calculated from each Stokes parameter curve Previously saved data can be recalled from the measurement screen by clicking the Load button Once the user chooses the desired file the data will be displayed on the screen For JME or MMM files the user can use the pull down menu to change the parameter displayed in the second graph Note Files generated by JME MMM or PS methods can be recalled from any of those measurement screens but not from the wavelength scanning method screen To start a new measurement with the same laser setup click Start again To change the laser setup before a new measurement click Laser Setup to bring up the laser setup window Manual mode If the laser type is set as Manually tuned the manual mode box in the interface will be enabled Figure 21 e Click the Start button in the manual mode box to start the measurement e The start wavelength entered from External Laser Setup will appear in the Manual Mode box Manually tune the external laser to this wavelength e Click Next to execute the measurement process for this wavelength When the measurement 1s finished the next wavelength in the sequence will appear in the box e Tune the external laser to the next measurement wavelength then click Next for the next measurement e When measurement is completed
18. on position e Press the button to bring up the main PMD measurement menu Figure 47A and B Use the up and down arrow keys A V to scroll through the options Measure PMD Load Setup or Load Data Press to select the highlighted option and proceed to the next step e To begin a new measurement select Measure PMD PMD measurement will begin using the Jones matrix method with the current laser setup parameters see Load Setup step for directions on how to change laser setup parameters During testing the screen shown in Figure 47D is displayed Pressing during testing will terminate a test in progress and return the display to Figure 47A Otherwise after testing is complete measurement results will be displayed Figure 47F e To recall stored data from an earlier measurement select Load Data After 4 is pressed the file selection screen Figure 47E is displayed Use the up and down arrow keys A V to select the desired file number then press J The recalled measurement data will be displayed on a measurement data display screen Figure 47F e To recall a stored laser and wavelength setup file select Load Setup Figure 47B After J is pressed the file selection screen Figure 47C is displayed Use the up and down arrow keys A to select the desired file number then press to load the selected file This data would be a TLS file After it is recalled the settings can be viewed
19. to the PSGA via GPIB cable if a PC is connected the PSGA cannot control the external laser or communicate with the PC The GPIB address of the PSGA is 0 when it is used as a GPIB controller The correct GPIB address of the external laser to be controlled must be set in the setup dialog window Figure 55 41 PC Mode the remote PC functions as the GPIB controller with the PSGA 101A as one of the GPIB devices under remote control In this case the user should set a GPIB address between 1 and 30 for the PSGA 101A and the correct GPIB address for the external laser being controlled by the PSGA in the setup dialog window Figure 55 The GPIB driver program IRQ exe should be run on the PC to support this mode Figure 56 otherwise the PSGA cannot control the external laser to finish measurements Please set the correct PSGA GPIB address before attempting any measurements or control Figure 56 Control interface of IRQ exe Document GP UM PSGA 101A 12 Page 72 of 86 After setting up the proper connections and operation modes the user can perform different measurements using the control commands given in Sections 9 3 9 9 9 2 Ethernet Control The PSGA 101A uses a TCP Server Client to implement Ethernet control The PSGA has a TCP server which can receive requests from a TCP client and send back responses During setup the PSGA s Ethernet hardware connection should be in place There is a network socket located on the rea
20. 283 Power 1 352dBm Figure 15 Polarization parameters of input light Document GP UM PSGA 101A 12 Page 22 of 86 5 3 4 Poincar Sphere Display The Poincare Sphere display can be controlled using the on screen buttons under the sphere Button functions are listed below Left Right Up Down Home Clear Zin ZOut PSA PSG Point Trace Rotates the sphere around the S3 axis ina clockwise counterclockwise direction Rotates the sphere around the S2 axis ina clockwise counterclockwise direction Restores the sphere s default perspective orientation and size Clears all points or traces from the sphere Zooms the sphere in out Selects the SOP data to be displayed on the Poincare Sphere PSA PSA input polarization PSG PSG output polarization Displays SOP data as individual or connected points Please note that any change to the Poincar Sphere display during standard PSA operation will clear the sphere To maintain existing points on the sphere while manipulating the sphere display use the long term measurement function see section 6 5 Document GP UM PSGA 101A 12 Page 23 of 86 Section 6 Measurements 6 1 Polarization Mode Dispersion PMD Measurement 6 1 1 Introduction In an ideal circularly symmetric fiber light in any polarization state would propagate with the same velocity However real fibers are not perfectly circular and are subject to local stresses consequently p
21. ADIE Moas Ur meh aean n a eee NR 53 67 Beat leneth Measurement eeen aen aen E EAEE A E aot 54 Section 7 Front Panels OO OERI 57 Section 8 Internal Tunable Laser Optional ccc ccccccsssseeeccccceeccaaeeeeeeccceeeeeaaaeeees 68 Section 9 Remote Control c cccccceccscosceccsccsceecsccececcecescsccsceecascncescascecescuccscescascsces 71 9 1 a Cee Mung Ren er ene Tern to 71 9 2 Ethernet Contr secoecicseckcdivcadsnsdeaclaceecgenesebs avtsesieecdeswiaseiecdingedeseisaviscobeavieselawielan 73 9 3 PSG GPIB Ethernet Commands c cccesceccsccsceccsccscececcsccscsececcscscacess 75 9 4 PSA GPIB Ethernet Commands c cccesceccscesceccecceceecaccscesceccsccscescacens 76 9 5 PMD PDL scan GPIB Ethernet Commands ccccccccacceccececceccecescescecees 77 9 6 PDL single wavelength measurement GPIB Ethernet Command 79 9 7 Wavelength Setup Commands for PMD and PDL measurement 80 9 8 Internal tunable laser commands ccceccccacceccecceccceccececceccecescescecescescecees 8 1 9 9 Enor DeM aa Seen harrahs cae woes Manse aai a reat A 83 Section 10 Technical Support and Factory Service Information cccccceeeeeeeeees 84 Document GP UM PSGA 101A 12 Page 4 of 86 Section 1 Specifications Operating wavelength range SOP generation accuracy SOP repeatability Azimuth amp ellipticity angle accuracy Stokes vector accur
22. D measurement using wavelength scanning method GP UM PSGA 101A 12 Page 35 of 86 e Set the value of the mode coupling constant k in the K factor box in the Setup section on the right of the screen k is equal to 1 in the absence of strong mode coupling and to 0 82 for the limit of strong mode coupling The default value of k is 0 82 e Set the parameter delta range is O 1 Once a wavelength scanning response has been measured it must be analyzed to identify and count the peaks and valleys extrema Delta is a minimum feature size parameter defining the magnitude change used to differentiate a peak from an adjacent valley The default value of this parameter is 0 05 e Select the calculation method The average DGD PMD can be calculated as PMD KN DAA 6 6 2 A 4 Je where Ne is the number of extrema 1 For the First to Last method A is the wavelength of the first extremum and is the wavelength of the last extremum 11 For the Full Scan method a is the start wavelength of the scan and p is the end wavelength of the scan The Full scan method should be used for the measurement of single mode fiber or DUTs with variable PMD values and strong mode coupling For optical components PM fiber or other DUTs with fixed PMD values and weak mode coupling the First to Last method can provide greater accuracy e Click the Start button to begin measurement The
23. Jones matrix of the DUT is measured by measuring the polarization states of the DUT outputs corresponding to different input polarization states generated by the PSG e Ifthe Mueller matrix of the DUT is moo Mo Mp2 M3 mMm My MQ My3 m M2 M22 M23 M39 63 M32 M33 Then the PDL can be calculated as Pi Moo moi mop EX m93 PDL 10x log 24 10 x log 20 N U 02 0 6 7 Puas Moo m9 pE moz Be mo e Ifthe measured Jones matrix of the DUT is J BS Ja J Jz let M 4 if a el Ja Jy J J Ms My Then the PDL of the DUT can be calculated as follows rl PDL 10 logi 6 8 r Document GP UM PSGA 101A 12 Page 37 of 86 Where m M 99 m M 9 2 a DE m 1 M77 M 2M2 are the eigenvalues of matrix M Differences between Mueller matrix and Jones matrix methods If different polarization states with the same power pass through an optical device the output power will generally be polarization dependent because of the PDL of the device If power variations are measured for at least four non degenerate polarization states then the PDL can be calculated using the Mueller matrix method Because the Mueller matrix method for PDL measurement is based on measurement of power variations the measurement accuracy is insensitive to polarization changes for example because of fiber movement between the PSG and PSA However any PSG output power variation due to fluctuation of la
24. Light Off Status lon Channel Current Channel 1550 12 nm 193 40 THz Cycle Action onn QUE Figure 53 Internal tunable laser source setup interface Table 3 Internal tunable laser source control options Light On Light Off Turns Laser on or off For the laser to turn on both the laser key above the main power switch on the front panel and the Light On Light Off button in this setup window must be in the on position Current Channel Sets the channel number wavelength of internal laser the corresponding wavelength and frequency are shown in the text boxes to the right of the Set button after Set is clicked Current Channel Reads the current channel wavelength frequency of internal laser output Document GP UM PSGA 101A 12 Page 68 of 86 Cycle function keys Used to set parameters for a wavelength scan Set Cycle Sets the number of times to perform the scan range 1s 1 999 et Dwel F p Sets the dwell time per state during a scan Can only be used when cycle action is set to auto nnnn is 20 3600 ms Sets the start channel of a sweep nn 1 89 Sets the end channel of a sweep nn 1 89 Set Step Sets the step size number of channels per step nn 1 89 Repeat option One way The scan starts at the designated start wavelength and ends at the designated end wavelength This process is repeated the number of times set in the Set Cycle box A One way Two way
25. M PSGA 101A 12 Page 70 of 86 Section 9 Remote Control The PSGA 101A can be remote controlled through either the GPIB or ETHERNET ports on the rear panel 9 1 GPIB Control Figure 54 Configuration for GPIB control using PC The typical configuration for GPIB control of the PSGA and an external tunable laser is shown in Figure 54 After the hardware connections are made proceed through the following steps e Select GPIB setup from the Setup menu Figure 55a The GPIB setup dialog window will appear Figure 55b and c she Measurements KG _e PSG Ctra PSA Ctra PER Ctrl F GPIB Mode 2 PC PC as controler PC PC as controller _ No PC PSGA as GPIB controller P GA PC as controller GPIB Address a 1 30 Internal TLS Ctrl I GPIB Ctr B a Figure 55 GPIB setup interface Document GP UM PSGA 101A 12 Page 71 of 86 e Set the GPIB addresses of the PSGA 101A and the external laser source if using one e Select the GPIB mode PC mode or No PC mode G No PC Mode PSGA Mode The PSGA acts as the GPIB controller it controls the other GPIB devices In this mode no other PC is connected to the PSGA 101A through a GPIB connection Without an external PC the PSGA can be used as a GPIB controller to control external lasers through GPIB cables If this mode is to be used no external PC can be connected
26. Making Light Work Lighter xX Lanal Dhnatarnure EFE FEVE CAN E E EIJ TEUJE MUJ C o r por ation PSGA 101A Polarization Measurement System PolaWise Operation Manual 22522 Os 00 9 5228 Edison Ave os Nov 5 2010 General Photonics Corp Ph 909 590 5473 Fax 909 902 5536 Chino CA 91710 USA www generalphotonics com Document GP UM PSGA 101A 12 Page 1 of 86 WARRANTY All of General Photonics products have been inspected and found to comply with our stringent quality assurance standards before shipping If any damage occurs during shipment please contact the carrier and inform us or our distributors as soon as possible Please do not under any circumstances attempt user repair of any General Photonics product To avoid further damage any repair of defective products must be performed by well trained engineers General Photonics warrants that this product will be free from defects in materials or workmanship for a period of one year from the date of original shipment listed on the certificate of quality or packing list enclosed with the original shipment A product found to be defective during the warranty period will be repaired or replaced at no charge at General Photonics option If a problem is found please contact General Photonics for assistance If necessary return the defective product freight prepaid clearly labeled with the RMA number with as complete a description of th
27. Matrix Measurement Beat Length Measurement w PSG PER Measurement Longterm Measurement Angle Measurement a Measurement menu b Long term measurement setup Figure 38 Long Term Measurement selection Select a measurement option from the Option pull down menu Free Run The PSGA records the number of SOP points specified in the Point box at the fastest possible sampling rate sampling rate is determined by the currently selected PSA operation mode high speed or high precision See Section 5 3 2 for details Timed The PSGA records the number of SOP points specified in the Point box at a rate of one sample per period with the period interval between measurements specified in the period box in units of seconds Document GP UM PSGA 101A 12 Page 51 of 86 e Specify measurement parameters Point The total number of points to be measured must be specified in both measurement modes Period s The time interval between two adjacent SOP measurements in timed measurement mode e Click START to begin measurement SOP points will appear on the Poincar sphere as they are recorded e Once a measurement is completed the data can be saved by clicking the Save button The user will be prompted to input a file name and location for the saved data Previously saved long term SOP data can be recalled from this screen by clicking the Load button Once the user chooses the d
28. OPMD gt Measured by Mueller Matrix method Document GP UM PSGA Il01A 12 Page 5 of 86 External storage USB removable storage media flash drive Software Control display program included Optical Connectors Laser Output and PSG input output FC PC FC APC SC PC or SC APC PSA Input FC free space Dimensions 2U 19 inch 3 4 rack width 3 5 H x 14 W x 14 L Document GP UM PSGA 101A 12 Page 6 of 86 Section 2 Overview The PSGA 101A PolaWise is a complete polarization measurement system for fiber optic applications based on General Photonics patented magneto optic polarization generation and analysis technology and designed for accurate characterization of all polarization related properties of light sources and optical materials Its major functions include polarization state generation PSG polarization state analysis PSA polarization extinction ratio PER measurement polarization dependent loss PDL measurement and polarization mode dispersion PMD measurement The instrument has three display options The primary one is the flip top LCD graphic display for self contained use of all graphic user interface based instrument control and data display options An external monitor can also be used via the VGA port The front panel 2x20 character LCD allows push button operation of the instrument for simple measurements that do not require a graphic display The internal tunable laser included in the standard
29. Page 3 of 86 Table of Contents DECOM l SPECIICAM OMS x sedsceroec nire ee r EE a a a a i E a AAS 5 EE E E a R E E A a es 7 SecHon o PEauire Desc PON ecuria e AN 8 SEO DUCA CUES axsu sso e r O A r e eA OONO EE rT 8 32 Elec ea Peanut E a a a oi 10 Section 4 General Instructions cccecceccecccceccecccccceccecesceccscescecceceecesssceecesescascseeces 12 4A UNPACKING censenda e S en Suge daaaeensiade eee 12 A ZAG DING Starod seia a E ET A R S 12 Section 5 Polarization State Generation and AnalySIS cccccccccssssessssssseeeeeeceeeeeeeeeaaaas 16 5 1 Polarization Parameters ct saccaviccatacaecee seid oatce esac aed ole odio Sa babe via Sata Las oleh bso oes 16 5 2 Polarization State Generator PSG Module cc cecccccccccceeeeeseeeeeeeeeeeeaas 18 5 3 Polarization State Analyzer PSA Module ccc cesessssseeeeeeeeeeeeeeeeeeeeeaaaaas 20 Section 6 Measurements cccccceccccccceccececcecceccecsceccecescecseceececusceecessecusceseseaecesescaceeees 24 6 1 Polarization Mode Dispersion PMD Measurement ccccceeeesseeeeeeeeees 24 6 2 Polarization Dependent Loss PDL Measurement cc ceeccccccceeeesseeeeeeeees 37 6 3 Polarization Extinction Ratio PER Measurement ccccccccccceeseesseeeeeeeees 43 6 4 Mueller Matrix measurement cccsscsccscosceececcscscaccsccscscceccsceccsccscascacens 47 6 5 Lons Termi Nieasurement 1 0 incre ieeti deo tanned 51 6 6
30. above The angle between the selected points will be calculated and displayed in the adjacent box Clicking Reset clears all markers Document GP UM PSGA 101A 12 Page 53 of 86 e The Angle Measurement function can be terminated by clicking the Exit button The angle measurement interface box will be replaced by the PSG interface box 6 7 Beat length Measurement Beat length is important because it indicates how well a fiber maintains polarization It is a measure of how fast the two orthogonal modes become decoupled and thus cease to exchange energy Fibers with short beat lengths preserve polarization more strongly than those with long beat lengths For bowtie type PM fibers beat lengths are typically only a few millimeters whereas for standard non PM single mode fibers beat lengths are on the order of tens of meters 6 7 1 Principle of Beat Length Beat length Lg is defined as the ratio of the wavelength of the transmitted light to the fiber s phase birefringence An A Lg ie 6 11 However the differential group delay DGD measured by the PSGA 101A system is related to the group birefringence Ang rather than to the phase birefringence see formula 6 12 DGD An L c 6 12 where L is the propagation distance and c is the speed of light The relationship between phase and group birefringence 1s dAn An ie ae 6 14 So the beat length can be calculated from the measured DGD _ A Le DGD c dAn a
31. acy DOP measurement accuracy PER dynamic range PER axis accuracy PMD measurement range PDL measurement range Accuracy DGD SOPMD PDL DGD SOPMD PDL DGD SOPMD PDL Repeatability Resolution PMD Internal tunable laser Wavelength tuning step Operating power range Optical power accuracy Optical power damage threshold Operating temperature Storage temperature Power supply Universal accepts either Computer interface Displays 1440 to 1620 nm standard 1 on Poincar Sphere 41 lt 0257 0 5 1 gt 40 dB Input Power gt 10 dBm 027 1 fs to 10 ps Internal tunable laser 1 fs to 400 ps External laser 0 01nm lt Agtep lt 10 nm 0 to 40 dB Input power gt 10 dBm 1fs DGD 0 5 SOPMD 1 0 05 dB PDL 2 0 03 fs 0 3ps 0 04 dB 1 fs 1550nm Astep 2nm 0 005 ps 1550nm Astep 2nm 0 01 dB lt 0 1 ps 1528 to 1563 nm 50 GHz minimum for internal tunable laser 40 to 2 dBm 0 25 dB 300 mW 5 40 C 20 60 C 100 120 VAC 50 60 Hz or 200 240 VAC 50 60 Hz GPIB Ethernet 8 flip top graphic LCD 2 x 20 character front panel LCD Specifications listed here apply to the standard 1440 1620nm model Contact General Photonics regarding other wavelengths At 2340 5 C gt DOP measurement accuracy for C and L bands Averaged over 10 steps with wavelength step size 2nm for DGD 0 1nm for S
32. arameter S1 S2 or S3 Returns the measurement O high speed 1 high precision mode m Al i wavelength Note Parameters or units in brackets are optional If they are omitted the default value will be used For the commands in this table the default unit is dBm Document GP UM PSGA 101A 12 Page 76 of 86 9 5 PMD PDL scan GPIB Ethernet Commands Setup Commands Control Command PMD MTD n Sets the PMD measurement method E00 n measurement option E02 ifn is omitted or is a 0 Jones matrix eigenanalysis value other than 0 1 2 or 3 1 PSA method 2 Mueller Matrix 3 Wavelength Scanning Method PMD TLS n Sets the type of tunable laser to be used for PMD E00 E02 E06 measurement laser option 0 manual mode 1 internal TLS 2 Agilent TLS PMD BGN Starts PMD measurement E00 E70 E71 E72 PMD END Stops PMD measurement PMD NEX Begins next measurement for manual mode PMD DWL ff f Sets the laser delay in seconds e g 10 0 This command used only for external laser Range 0 99s Document GP UM PSGA 101A 12 Page 77 of 86 Status Report Commands Report Command PMD RDY Queries whether PMD data are 0 available E08 E09 E50 E51 available 1 not ready E52 E53 E54 E55 Error code see section 9 9 E56 PMD SCN For the wavelength scanning FEFFE fee FEFE FEF EEEE EEE E50 E51 E52 method returns PMD values calculated from variations in sl s2 and s3 respectively PMD NUM Returns
33. arization Extinction Ratio PER Measurement To minimize polarization dependent effects it is often desirable to maintain a constant state of polarization as light propagates through an optical system With regard to such systems polarization extinction ratio PER or polarization crosstalk 1s a measure of the degree to which the light is confined in the principal polarization mode It is defined as the ratio of the power in the principal polarization mode to the power in the orthogonal polarization mode after propagation through the system expressed in dB 6 3 1 PER measurement principle Polarization maintaining PM optical fibers have an optical slow axis defined by a strong linear birefringence If light input to an ideal PM fiber is polarized along the fiber s optical axis the polarization state will be maintained during propagation through the fiber However if it 1s misaligned or is not fully polarized the component polarized along the slow axis propagates at a different speed than the component polarized along the fast axis Thus the polarization state of the light changes with the relative phase delay between the two components as it propagates through the fiber For the case of a linearly polarized light beam launched into a PM fiber with its polarization axis rotated by an angle 8 from the PM fiber s slow axis as shown in Figure 28 the extinction ratio due to the misalignment can be calculated as PER 10log tan 6
34. arization mode dispersion vector W M W 2 2 and PSP is the principal state of polarization at frequency Ox The SOPMDpwms is the root mean square RMS of the SOPMD values over a given wavelength range at a certain time Document GP UM PSGA 101A 12 Page 25 of 86 6 1 2 PMD measurement principles for JME MMM and PS The JME MMM and PS methods all use the same measured data to calculate PMD Setup and measurement procedures are therefore identical for the three methods At a given wavelength the PSG generates a set of distinct polarization states for example the Jones Matrix method uses the three linear polarization states 0 45 and 90 For each polarization state the polarization state analyzer measures the corresponding Jones vector or Stokes parameters of the polarization state of light after the DUT Figure 16 This procedure is repeated for each wavelength in the set specified in the measurement setup The JME MMM and PS methods then use different sets of calculations to determine the wavelength dependence of the differential group delay DGD principal states of polarization PSP and second order PMD from the wavelength dependence of the Jones vector or Stokes parameters H SH x or Linear 0 eo i Se Linear 45 J gt q j Iy a V3 ra A Q or Sor Q Linear 90 z Q bi 03 Jones Stokes Figure 16 PMD measurement data acquisition for Jones Matrix Eigenanalysis Jones Matrix Ei
35. e e If using the A scan method with the PSGA s internal tunable laser select PER from the Setup menu Internal Tunable Laser Scan Setup mie Measurements PSG Ctrl G PSA Ctrl PER Ctrl F Start Channel Mo 96 10 THe 1528 77 nm Step Size fi pT Step Number 2 00 End Channel le 191 70 THz 1563 56 nm i Cancel Internal TLS Ctrl I GPIB Ctrl B Figure 31 PER laser setup Select the start channel step size and step number for the wavelength scan e Select PER Measurement from the Measurements menu Figure 32 Document GP UM PSGA 101A 12 Page 45 of 86 Display Help PRIOVPOL Mueller Matrix PRIOVPOL Jones Matrix PER PRIOVPOL Jones Matrix Fast Mode PER START PMO Poincare Sphere Analysis PER dE Azimuth 3 PMD Wavelength Scanning Method StretchiHeat Pa aA PDL Jones Matris Single YL POL Mueller Matrix Single YL Mueller Matris Measurement Beat Length Measurement w PSG FER Measurement Longterm Measurement Angle Measurement Figure 32 PER measurement selection The PER measurement box will replace the PSG box in the bottom right corner of the main interface screen e As mentioned in the previous section PER is determined by measuring output polarization rotation caused by changes in the relative phase between the two polarization components The changes in relative phase can be caused either by variation in input wa
36. e Use the left and right arrow keys lt 4 to move to option 3 then press to save the file xx PSG xx PDL xx PMD or xx TLS e xx PSG is used to store the current PSG setup xx PMD is used to store PMD measurement results xx TLS is used to store the laser and wavelength setup for PMD measurement xx PDL is used to store PDL measurement results e If the file number chosen contains previously saved data the user will be asked whether or not to overwrite the file 1 Default position of cursor is No 11 Use the left and right arrow keys lt 4 to select Yes or No If the answer is Yes the existing file is overwritten otherwise the cursor returns to option 2 to allow the user to select another number Document GP UM PSGA 101A 12 Page 67 of 86 Section 8 Internal Tunable Laser Optional To facilitate different measurements using wavelength scanning related procedures the standard configuration of the PSGA 101A includes an internal tunable laser The tunable laser can be used by itself as an independent light source or in conjunction with the other PSGA modules PSG and PSA to perform different measurements To set up the internal tunable laser s operation parameters select Internal TLS under the Setup menu in the menu bar at the top of the main control interface The laser setup window Figure 53 will appear The control options are described below Internal Tunable Laser Source Laser
37. e determined by the extinction ratio of the polarizer If the SOP of the input light is close to orthogonal to the polarizer axis the light output can be very low To solve this problem the PSGA includes a 90 controllable polarization rotator located before the PSG input Clicking the Adjust PSG Power button in the PSG control interface box Figure 10 rotates the polarization plane of the input light by 90 changing the PSG output power accordingly This function should be used if the initial PSG output power is very low e PSG Scanning Mode The PSG can be set to scan its output polarization state through the 6 Poincar sphere pole states in the following sequence LHP 45 45 LVP LHC and RHC The dwell time at each state in units of seconds can be set from the PSG Setup interface Figure 11 Document GP UM PSGA 101A 12 Page 19 of 86 mite Measurements Setup e Wavyelengthtnm Scan intervalish 0 1 1000 J1 Ctr4 G Ctril Ctri R PSA PER Internal TLS Ctrl I PIB Ctr E Figure 11 PSG setup for scanning mode Once the dwell time is set choosing scan from the State menu Figure 10 will start the scan 5 3 Polarization State Analyzer PSA Module The polarization state analyzer PSA module inside the PSGA 101A can be used to analyze polarization related parameters properties for free space setups as well as fiber guided light A special FC adapter with a c
38. e problem as possible The repaired or replacement product will be returned freight prepaid as soon as possible The above warranty specifically excludes products that have been repaired or modified by non manufacturer authorized personnel as well as damage caused by misuse abuse improper storage or handling or acts of nature This warranty is in lieu of all other warranties expressed or implied General Photonics will not be liable for any indirect or consequential damages or losses resulting from the use of its products Document GP UM PSGA 101A 12 Page 2 of 86 SAFETY CONSIDERATIONS The following safety precautions must be observed during operation service and repair of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument General Photonics Corp assumes no liability for customers failure to comply with these requirements e Before operation the user should inspect the instrument and review the manual carefully e The instrument s rear panel includes a chassis ground terminal for electrical safety e Make sure that the instrument is in a secured work environment in terms of temperature humidity electrical power hazard due to fire or shock etc for proper operation e Standard laser safety procedures should be followed during operation Document GP UM PSGA 101A 12
39. ed and displayed in the PER measurement box at the bottom right of the main screen It should be noted that if the PMD of the PM fiber is greater than 10ps the PSGA cannot identify the slow or fast axis of the PM fiber File Setup Measurements Display Help PSA ENABLE PSA azimuth v 29 0986 s2 7 0 0313 s3 0 0949 Power 0 601dem 60 Left Right Up Down Home Clear zin zout Draw Option PER 21 54 dB Azimuth f67 11 Slow Psa O PSG Point Trace Method scar E 2 start PwPolawise EE 12 03 AM Figure 33 PER Measurement Results To measure the PER of a length of PM fiber independent of connector effects etc the following iterative procedure can be used e After the first measurement is completed carefully adjust the polarization controller to move the polarization state to the center of the circle e Press PER START and repeat the measurement e Adjust the polarization controller again and repeat until the highest PER measurement is found 6 4 Mueller Matrix measurement The PSGA can measure the Mueller matrix of a DUT Document GP UM PSGA 101A 12 Page 47 of 86 6 4 1 Principle of Mueller matrix measurement yd 2 4 Linear 0 yo Soo S10 S20 S30 Linear 45 p gt Sor S11 S21 S31 Linear 45 K gt So2 S12 S22 S32 Linear 90 Gos SiS Ss LHC es Soa S14 S24 S34 RHC is Sos Sis S25 S35 Figure 34 Principle of Mueller matrix measureme
40. er pull down menus Note The sum of Start_channel Step _size Step_ number must be less than 89 Also the step size chosen will affect the range and accuracy of the measurement Please refer to the wavelength step size selection description in Section 6 1 2 for directions on how to choose the correct step size for measurement of a particular device under test DUT If the external laser or manually tuned laser is selected set Start wavelength End wavelength Wavelength step and Laser output power by typing the values in the Document GP UM PSGA 101A 12 Page 32 of 86 corresponding boxes Note Please refer to the wavelength step size selection description in Section 6 1 2 for directions on how to choose the correct wavelength step Click the Ok button to save the laser setup and bring up the PMD measurement interface Figure 20 Manual Mode Tune laser wavelength nm to 1520 000 Numerical Values SOPMD Figure 20 PMD measurement interface Automatic mode Internal tunable laser or PSGA controlled external laser Click the Start Stop button to begin the PMD measurement DGD and second order PMD vs wavelength plots will be drawn as the measurement proceeds Once the measurement is finished DGD and second order PMD SOPMD values will be displayed at the bottom of the screen If the Jones Matrix method or Mueller Matrix method are used the wavelength dependence o
41. esired file the data will be displayed on the Poincar sphere e Poincar sphere data from a completed or in progress long term measurement can be viewed from different vantage points by using the left a s 29 66 right up down ZIn and ZOut buttons under the sphere display Recorded data points will rotate or zoom with the sphere Note During measurement the PSA plots points at its normal speed but only recorded points will be maintained on the sphere during sphere manipulation For a timed measurement depending on the sampling period chosen this can cause most of the points to disappear as the sphere is rotated or zoomed Free Run mode is better for tracking fast polarization changes e The Long Term Measurement function can be terminated by clicking the Exit button The long term measurement interface box will be replaced by the PSG control box Document GP UM PSGA 101A 12 Page 52 of 86 6 6 Angle Measurement The PSGA 101A can measure the angle between specified points on the Poincar sphere Angle Measurement Procedure Display Help PRIDOVPOL Mueller Matrix PMO POL Jones Matrix PRIOVPDL Jones Matrix Fast Mode PMO Poincare Sphere Analysis PMD Wavelength Scanning POL Jones Matrix Single YL POL Mueller Matrix Single WL Mueller Matrix Measurement Beat Length Measurement w PSG FER Measurement Longterm Measurement Angle Measurement start Fv
42. f the SOPMD PDL PSP Q absolute value of the parallel component of SOPMD absolute value of the perpendicular component of SOPMD and phase change are measured concurrently with DGD The pull down menu in the Graph box can be used to select the parameter to be displayed in the second graph If PSP is selected the graph will display the wavelength dependence of the Stokes parameters S1 green S2 red and S3 yellow of the PSP The pull down menus in the Numerical Values box can be used to select the average RMS standard deviation maximum minimum or current value of DGD PDL SOPMD Q or PSP Stokes parameters to be displayed in the adjoining box If current is selected before measurement begins the box will update as each point is measured To hide the measurement window and return to the main screen Poincar sphere display click Hide The measurement window can be recovered by clicking Display in the menu bar of the main screen Once a measurement is completed the data can be saved by clicking the Save button The user will be prompted to input a file name and location for the saved data Document GP UM PSGA 101A 12 Page 33 of 86 Note Saved files will include all of the measured data For JME or MMM the file includes DGD SOPMD PDL PSP 9 Q and phase change vs wavelength A Poincar Sphere method file will include the same set of data as JME and MMM except for PDL A wavelength scanning
43. fff measured wavelength range PMD PDL MIN Returns the MIN PDL over FEEF fff measured wavelength range Document GP UM PSGA 101A 12 Page 78 of 86 9 6 PDL single wavelength measurement GPIB Ethernet Commands Setup Commands Control Command Error PDL MTD n Sets the measurement method E00 E02 E04 0 Jones matrix method 1 Mueller matrix method PDL BGN Starts PDL measurement PDL END Stops PDL measurement Status Report Commands Report Command PDL RDY Queries whether PDL data are 0 available E08 E09 E61 E62 available 1 not ready PDL Returns the PDL value ff ff E64 This command is only available in single wavelength mode Document GP UM PSGA 101A 12 Page 79 of 86 9 7 Wavelength Setup Commands for PMD and PDL measurement Setup Commands Control Command MEA CHN SIN nn Sets laser channel to nn Used for single E00 E02 E06 wavelength PDL measurement MEA CHN LWR nn Sets the start channel for a scan E00 E02 E06 Sets the step size of channels for a scan po External ase for single wavelength PDL measurement MEA WAL UPR ffff ff Sets the end wavelength for a scan E00 E02 E06 MEA WAL STP ffff ff Sets the wavelength step size for a scan E00 E02 E06 Status Report Commands Internal Tunable Laser MEA CHN SIN Returns current channel number single wavelength operation MEA CHN LWR Returns the start channel number MEA CHN UPR Returns the end channel number
44. for all wavelengths in the sequence entered in the external laser setup the Next button will revert to Start e Clicking Start will begin a new measurement Document GP UM PSGA 101A 12 Page 34 of 86 Once a measurement is completed the data can be saved by clicking the Save button The user will be prompted to input a file name and location for the saved data Previously saved PMD data can be recalled from this screen by clicking the Load button Once the user chooses the desired file the data will be displayed on the screen PMD Mueller Matrix Method 1 81 Manual Mode Tune laser wavelength nm CAN nnn 1 JTZ Wave an gth nm 0 10 549 000 JAF 1543 000 Wavelengthinm Graph Numerical Values soPmo SopmpD x amg 0 035 ps Figure 21 PMD measurement using a manually tuned laser source 6 1 6 PMD measurement procedure for wavelength scanning method Select PMD Wavelength Scanning from the Measurement menu Figure 18 After completing the laser setup see previous section the measurement screen will appear Note The Manually Tuned Laser option does not work with the Figure 22 wavelength scanning method Document PMD Wavelength Scanning 1 00 PMD Data PMD S1 1 065 PMD S2 1 072 PMD S3 ps ps Wavelength nm Method First to Last YWavyelen gth nm Laser Setup Wavelength nm Figure 22 PM
45. genanalysis data acquisition and analysis methods Tunable laser TLS is set to the first wavelength A PSG outputs three non degenerate polarization states Linear 0 45 90 For each state PSA measures the corresponding polarization state after the DUT Jones Matrix My A4 is calculated for A Process is repeated for the next wavelength Az Product P Mj A2 My 41 is calculated A e The poo 22 and corresponding fast psp t are determined from the eigenvalues and eigenvectors of Jones matrix I e Process is repeated for the next wavelength to get Mj A3 Document GP UM PSGA 101A 12 Page 26 of 86 are calculated Ay a poo 24 and the corresponding fast PSP Mike A A A A e SOPMD A is determined from pop 2 PSP yo e DGDs are averaged over to obtain PMD SOPMD A is averaged over A to obtain SOPMD yee ES pan 2t4 and pse Generalized Mueller Matrix Method data acquisition and analysis methods e Tunable laser TLS is set to the first wavelength A e PSG outputs six non degenerate polarization states Linear 0 45 90 RHC and LHC e For each state PSA measures the corresponding polarization state after the DUT e Mueller Matrix M A of DUT is calculated refer to section 6 4 1 e Process is repeated for the next wavelength Ao Ata lt 2 2 e The complex PMD M Az2 QO Q A 60 ae ath Re VWeW and PSP are calculated e Process
46. he PSG can generate six non degenerate polarization states linear horizontal and vertical LHP LVP linear 45 linear 45 RHC and LHC Individual states can be selected from the PSG State pull down menu on the PSG control interface box in the Document GP UM PSGA 101A 12 Page 18 of 86 bottom right corner of the screen Figure 10 The state will be generated as soon as it is selected The SOPs of these six states are wavelength and temperature dependent and have been accurately calibrated The Stokes parameters of the actual output SOP at the current temperature and the wavelength set in the PSG Setup screen Figure 11 are shown in the bottom line of the PSG control interface It should be noted that the SOP given here represents the polarization state of light at the output port of the internal PSG module before passing through any fiber This state is generally different from the SOP at the PSG output adapter on the PSGA front panel PSG OUT because the SM fiber between the internal PSG module and the PSG front panel output adapter can change the SOP of light passing through it Lo LOO PSG Power State T w Anm 7550 00 sli j1 000 52 0 002 Siar lo OW Figure 10 PSG state control interface e PSG output power optimization Because the PSG module uses a linear polarizer to define its input polarization state its output power depends on the polarization state of the light input to the polarizer with a rang
47. interface Options are 0 45 45 90 RHC LHC SCAN Document GP UM PSGA 101A 12 Page 59 of 86 In Scan mode the PSG will scan through the states in the following sequence 0 45 45 90 LHC RHC using the currently set dwell time at each step In Scan mode pressing will terminate the scanning process The output polarization will stay in the state it was in when was pressed Pressing Enter again will restart the scan 7 2 PSA control 1 High Speed p A PES A v L B Wavelength 1550 00nm d Figure 45 PSA front panel control sequence Press the PSA key to bring up the PSA measurement mode selection screen Figure 45A Use the up and down arrow keys A V to select High Speed or High Precision measurement mode If High Speed is selected the wavelength of the input light must be specified Press to proceed to the wavelength setting screen Figure 45B From the screen shown in Figure 45B use the arrow keys to set the wavelength and to accept it and proceed to a data display screen If High precision is selected press to proceed directly to a data display screen After the wavelength is set for High Speed mode or after High Precision is selected the first data display screen shows the current SOP as Stokes parameters and DOP of the input light Figure 45C The V key toggles the data display to the second screen Figure 45D which d
48. internal TLS Document GP UM PSGA 101A 12 Page 64 of 86 7 7 Wavelength wavelength scan setup for PMD measurement 7 7 1 Wavelength setup for the internal tunable laser 1 Single Channel Single Channel 1 B A ROTON 1 Start Ch 1 3 Step No 10 C DESC He Stop Ch 21 D 4 Dwell Time 10 0 Sec Figure 50 Internal laser source wavelength selection control sequence Press A to bring up the main wavelength setup selection screen Figure 50A e Use the up and down arrow keys A Y to select Single Channel setup or Channel Scan setup Press to select the highlighted option e If Single Channel is selected the display proceeds to the channel selection screen Figure 50B Use the up and down arrow keys A V to set the channel number and to execute the setting e If Channel Scan is selected the display proceeds to the first scan setup screen Figure 50C Use the arrow keys to set the start channel scanning step step number and dwell time for PMD measurement Press to execute the setting Document GP UM PSGA 101A 12 Page 65 of 86 7 7 2 Wavelength setup for an external tunable laser source 1 Single Wavelength B 2 Wavelength Scan 1 Start WL 1540 00nm 2 Step 1 00nm 4 Dwell Time 10 0 Sec Figure 51 External laser source wavelength selection control sequence Press A to bring up the main wavelength setup selection screen Figure 51A e Use the up and down
49. ion Reason for return of goods please list any specific problems Document GP UM PSGA 101A 12 Page 86 of 86
50. is repeated for the next wavelength to get M Asz Ay A 2 calculated from M A and e ponti 2 ds and the corresponding PSP are calculated A e SOPMD A determined from pan t psp 4 4 f 1 and PSP gt Ay Az e DGDs are averaged over to obtain PMD SOPMD A is averaged over A to obtain SOPMD parf Poincar Sphere Analysis data acquisition and analysis methods e Tunable laser TLS is set to the first wavelength A e PSG outputs three non degenerate polarization states Linear 0 linear 45 and RHC e PSA measures the corresponding polarization states H 1 Q A after DUT Document GP UM PSGA 101A 12 Page 27 of 86 e Process is repeated for the next wavelength A2 e The following are calculated from the measured normalized Stokes vectors h H e ea aa ae HxQ xv and hxgq C qxv e For each frequency increment the finite differences are computed Ah h A A A Ag q A q 4 AV V A V A AC E A E Ay A 2 4 2 Ay A A x l 2 5 e DGD a aine S Ag bA aren Fag AVv AG 2 Ao 2 2 2 2 e Average DGDs are averaged over A to obtain PMD SOPMD A is averaged over to obtain SOPMD Wavelength step size selection for PMD measurement using JME MMM or PS The accuracy of the JME method is influenced by drifting birefringence in the test path stability of the test path optical source incremental wa
51. isplays the optical power ellipticity angle O and azimuth angle w The A key toggles the display back to the Stokes parameter screen Document GP UM PSGA 101A 12 Page 60 of 86 7 3 PER measurement Note Only the scan measurement method can be used with front panel control Figure 46 PER measurement front panel control sequence e Press the key to bring up the PER measurement screen Figure 46A Any other processes currently in progress PSG scanning tunable laser scanning PSA PMD or PDL measurement will stop If a PSG scan was in progress the PSG output remains in the state 1t was in when the PER key was pressed e Turn the laser key on the top left of the front panel to the on position the internal tunable laser must be turned on e Press J to begin the measurement using the scan method default While testing is in progress the Start in the display will change to Testing Figure 46B When testing is complete the measured PER and angle will be displayed Document GP UM PSGA 101A 12 Page 61 of 86 7 4 PMD measurement Note Only the Jones matrix method can be used with front panel control 1 Measure PMD ee Pee gt Testing J A 2 Load Data METT Stop D 3 Load Setup B z E Yy File Name 1 File Name 1 C mj u Figure 47 PMD measurement front panel control sequence e If using the internal tunable laser check that the laser key above the main power button is in the
52. l 1 PSG State 0 C z 2 Load Setup ime 5 File Name 1 i D Figure 44 PSG front panel control sequence e Press the key to bring up the main PSG control menu Figure 44A The left arrow lt 4 key moves between options 1 and 2 e Option 1 With the PSG State option highlighted the up and down arrow keys A Y can be used to select the PSG output polarization state Options are 0 45 45 90 RHC LHC and SCAN Press ENTER center key in the arrow keypad to go to the PSG setup interface Figure 44C e Option 2 Load Setup is used to recall a stored settings file With 2 on the main menu highlighted press to select the PSG setup file to be loaded Figure 44B The up and down arrow keys A are used to scroll through available file numbers and is used to load the selected file e After the setup file is loaded the interface shown in Figure 44C is displayed e In the setup interface Figure 44C the arrow keys A V lt P can be used to enter values for the wavelength of the input light and the dwell time per state for the scanning mode After setting the values press to execute the settings and proceed to the SOP display interface Figure 44D e The SOP display interface Figure 44D shows the current PSG output state 0 45 45 90 RHC or LHC and its Stokes parameters e The up and down arrow keys A VW can be used to change the PSG output state from the SOP display
53. l Photonics will respond to all customer questions within 24 hours during regular business hours General Photonics can also be contacted by mail at General Photonics 5228 Edison Avenue Chino California 91710 USA Document GP UM PSGA 101A 12 Page 84 of 86 10 2 Factory Service Information The PSGA 101A Polarization Measurement System contains no user serviceable parts To obtain information regarding factory service contact General Photonics Corporation or your General Photonics representatives distributors Please have the following information available l Instrument model number and serial number 2 Description of the problem If the instrument is to be returned to General Photonics Corporation you will be given a RMA Number which you should reference in your shipping documents Please fill out a copy of the service form located on the following page and have the information ready when contacting General Photonics Corporation Return the completed service form with the instrument Related product warranty information can be found on the second page of the user manual Document GP UM PSGA 101A 12 Page 85 of 86 Service Form Making Light Work Lighter Lanc nn Diantnanre JEE FUE CAF E E EW CCST FIT C o r por ation Name Return Authorization Please obtain RMA prior to return of item Company Address Date Country Phone Number P O Number FAX Number Item s Being Returned Model Serial Descript
54. larization state The polarization ellipse is the elliptical trace made by the tip of the electric field vector of a light signal in the XY plane perpendicular to the light propagation direction z where the x y and z axes define a right handed coordinate system Generally the ellipse is characterized by its orientation and elongation A common parameterization uses the azimuth angle w the angle between the semi major axis of the ellipse and the x axis and the ellipticity angle y tan Emax Emin Where Emax and Emin are the lengths of the semi major axis and the semi minor axis respectively If the rotation of the electric field vector tip appears clockwise to an observer facing the incoming light the light 1s right hand polarized and its ellipticity angle is positive otherwise the light is left hand polarized and its ellipticity angle is negative The direction of rotation R L of the polarization is usually indicated by an arrow at the bottom right or bottom left of the polarization ellipse see Figure 8 KR S Figure 8 Right handed Polarization Ellipse Polarization states can also be graphically represented on a sphere of unit radius known as the Poincar sphere A polarization state corresponding to a polarization ellipse of azimuth angle yw and ellipticity angle y can be mapped to a point P with spherical coordinates 2w 2 1 The rectangular coordinates Si S2 S3 of point P are the normalized Stokes parameters of the p
55. ller Matrix Measurement Beat Length Measurement Beat Length Measurement PSG Ww PSG PER Measurement PER Measurement Longterm Measurement Longterm Measurement Angle Measurement Angle Measurement Figure 24 PDL measurement options on the Measurement menu Single wavelength measurements If PDL Jones Matrix Single WL or PDL Mueller Matrix Single WL is selected the single wavelength measurement interface window shown below appears PDL Single Measurement PDL Jones Matrix PDL Data Ainm 1550 Curent 0 42 Average 0 42 Count g Figure 25 Single wavelength PDL measurement Document GP UM PSGA 101A 12 Page 40 of 86 Input the measurement wavelength in the A box and the number of measurements to be averaged in the count box then click Start to begin measurement Make sure that the laser is set to the correct wavelength before starting the measurement see section 8 for directions on how to set the wavelength for the internal tunable laser The results will be displayed in the current result of last single measurement and average average of results from all measurements boxes The number of measurements to be averaged can be chosen to compensate for instabilities in the measurement setup Wavelength dependent measurement 1 Laser setup If a wavelength dependent measurement PMD PDL Jones Matrix or PMD PDL Mueller Matrix is selected a Laser Set
56. n and high speed High precision mode is the default operation mode It provides maximum precision with a low sampling rate 10 samples sec and does not require the wavelength of the input light to be specified High speed mode provides a high sampling rate 40 samples sec with slightly lower precision however the exact wavelength of the input light must be specified during setup PSA Setup procedure e Select PSA from the Setup menu Figure 14A The PSA Setup dialog window will pop up e Select high precision or high speed mode in the PSA Setup window Figure 14B e If high speed mode is selected the wavelength of the input light should be set for accurate measurement Document GP UM PSGA 101A 12 Page 21 of 86 mite Measurements Ctrl G Ctrl 4 PER Ctrl R Algorithm High Precision Internal TLS Ctrl I Wavelengthinm 1550 SPITE Ctrl B A B Figure 14 PSA Setup interface 5 3 3 Polarization Parameter Analysis Polarization related parameters are analyzed and displayed in real time in the PSA parameter status box in the middle right of the main screen Figure 15 Select the desired parameters from the pull down menus then click the PSA Enable Disable button to start stop measurement When the PSA is enabled SOP information is also displayed on the Poincar sphere and the 2 D PSA polarization ellipse display PSA PSA DISABLE s1 0 6803 s3 0 3
57. nctions are described in greater detail in the following sections Menu bar File Contains options to save or load long term measurement data print the current screen to a bitmap file or to exit the control program Setup Setup options for the polarization state generator PSG polarization state analyzer PSA polarization extinction ratio measurement PER laser setup internal tunable laser TLS and GPIB Measurements Measurement selection menu for PMD PDL PER Mueller matrix beat length and angle measurements and for long term polarization data recording Display Restores the most recently used PMD PDL measurement display screen if it has been hidden Soft keyboard keyboard icon at bottom right corner of screen Most PSGA 101A functions can be controlled via mouse However there are some instances in which the user may need to input information from a keyboard The PSGA 101 comes with an external keyboard which connects to the front panel of the instrument For more self contained operation the control program also includes a virtual keyboard which can be accessed by clicking the keyboard icon at the bottom right corner of the screen This brings up a pull up menu offering the choice of a small or large virtual keyboard as well as the option to hide the keyboard Poincar sphere display left half of the screen The Poincar sphere display is a graphical representation of the polarization state of either the PSG
58. nel The PSGA 101A includes Ethernet and GPIB interfaces for external computer operation of the system and data readout Control commands and instructions for remote control are listed in Section 9 Rear panel description RS 232 serial port not used in PSGA 101A Ethernet Ethernet interface port used for PSGA 101A remote control GPIB GPIB interface port used for PSGA 101A remote control VGA used to connect with external VGA monitor Line external AC supply input connector 110 V or 220 V BNC not currently used in PSGA 101A L chassis ground connector Document GP UM PSGA 101A 12 Page 11 of 86 Section 4 General Instructions Warnings Never look into the light source fiber connector when the light source is turned on THE OUTPUT LIGHT FROM A HIGH POWER LASER IS HARMFUL TO HUMAN EYES Please follow industry standard procedures when operating a high power laser source Since the light from the PSGA s internal tunable laser is invisible it is safer to turn it off before changing connections and when the laser is not in use The PSGA 101A is designed for accurate measurements Avoid water condensation or liquid spills during PSGA 101A storage and operation Check optical power level of the input optical beam to the PSA Make sure the optical power level at the input connector to the PSA is below 2 dBm 1 6 mW When powering the instrument off wait at least 20 30 seconds before powering it back on to avoid damage t
59. nt The PSG generates six non degenerate states Linear 0 45 45 90 LHC and RHC in sequence e The Stokes parameters S1 S2 S3 S4 S5 and S6 of these six PSG output states are calculated for wavelength A according to PSG calibration data The PSA measures the corresponding output Stokes parameters S1 S2 S3 S4 S5 and S6 without DUT Reference matrix Mer is calculated from the calculated and measured Stokes parameters using the following formula Mre S Psae Spsg SpsceS psc Where Si Sa So3 Su Si Si Sor So2 Sos Soa Sos So Spsa gt Si 512 S13 314 Die S16 and Spsc Si S2 Sig Sig Sis Si So Sa S93 Sa S25 Sa Sa Sa S93 Sa Sas S26 S31 S32 S33 S34 S35 S36 S31 S32 S33 S34 S35 S36 e The DUT is placed between the PSG and PSA and the procedure described above is repeated to obtain matrix Mx e The Mueller matrix of the DUT is calculated Mpur Mx M kef Document GP UM PSGA 101A 12 Page 48 of 86 6 4 2 Measurement setup for Mueller matrix measurement The setup for Mueller matrix measurement is shown in Figure 35 The light source can be the internal laser or an external laser source For free space measurement the FC adapter at the PSA input should be removed A pigtailed collimator connected to the PSG output should be used to generate a parallel light beam Align the position and orientation of the collimator to maximize the power received by the PSA In order to obtain the actual Mueller mat
60. o electrical components Be careful with the flip up graphic display screen Rapidly and repeatedly raising and lowering it may cause damage 4 1 Unpacking Inspect PSGA 101A for any physical damage due to shipping and transportation Contact carrier if any damage is found Check the packing list to see if any parts or accessories are missing Major accessories include power cord keyboard USB mouse fixed optical attenuator 10 dB and optical jumper cables normally FC PC to FC PC Avoid excess vibration environments when using the PSGA 101A system 4 2 Getting Started Setup procedure 1s described below Make sure local AC voltage matches the AC voltage requirement of the PSGA 101A system 100 240V 50 60Hz Connect power cord and plug it into wall receptacle Make sure the ground pin of the power cord is connected to earth ground Connect the mouse to one of the USB ports and the keyboard optional to the keyboard connector Document GP UM PSGA 101A 12 Page 12 of 86 4 Carefully slide off the metal cover for the LCD graphic display then slowly raise the display to a convenient viewing angle 5 Make sure that the optical path is correctly connected for the desired measurements including the optical source either external or internal 6 Turn on the main power switch Note If a flash drive is connected to a USB port during power up the PSGA will not recognize the mouse Please make sure to disconnect any fla
61. o the ferrule end for routine cleaning and maintenance without removing the entire adapter from the panel This feature helps avoid high insertion loss high return loss and measurement instability caused by dirty or contaminated connectors Since the PSA input is free space there is no internal ferrule that would need cleaning For the three connectors with internal ferrules each connector ferrule is contained in a universal connector interface consisting of a front piece that connects to the external fiber connector and a base piece that is mounted on the front panel of the instrument as shown in Figure 2 To clean a connector ferrule first make sure that no external connector is connected to the universal connector interface Then using a Phillips screwdriver remove the two small screws connecting the front and back parts of the adapter and carefully pull the front flange straight out Note never remove the adapter base from the Document GP UM PSGA 101A 12 Page 8 of 86 front panel The ferrule end should now be exposed Clean the ferrule using standard cleaning procedures compressed air or a fresh lint free tissue and alcohol taking care to avoid scratching the ferrule surface Finally replace the front flange position it so that the key notch faces up and the small alignment pin lines up with the hole in the base piece before pushing it in and the screws For frequent measurements we recommend that the user prepare a patch
62. o the front panel LCD When it is on the PSGA s GUI control interface is enabled and the front panel control is disabled In short the DISPLAY key is used to select the PSGA s user interface The PRINT key is only functional when the graphic display is enabled When PRINT is pressed the PSGA 101A will print the graphic display screen to a bmp file The user will be prompted to enter a name and location for the stored file Document GP UM PSGA 101A 12 Page 57 of 86 Front Panel Function Key Summary PSG Brings up PSG control options PSA Brings up PSA control options PER Begin setup for PER measurement PMD Begin setup for PMD measurement PDL Begin setup for PDL measurement PRINT Prints currently displayed screen on flip up graphic display to a bitmap file Can only be used with graphic display enabled STORE Store current settings PSG or laser settings or measured data PMD or PDL to a file Select wavelength settings for PMD measurement TLS Select laser source for PMD measurement DISPLAY Toggles PSGA between front panel and GUI user interfaces A lt 4 gt Arrow keys used to scroll through menus or enter numerical parameters M ENTER key in center of the arrow keys Used to select menu options or enter parameters Document GP UM PSGA 101A 12 Page 58 of 86 PSGA front panel control Please see section 6 for optical connection diagrams for the various measurements 7 1 PSG contro
63. olarization state represented by P with JS S S 1 Any polarization state can be represented as a point on the Poincar sphere and every point on the Poincar sphere represents a unique polarization state Figure 9 Document GP UM PSGA 101A 12 Page 17 of 86 Figure 9 Poincar sphere representation of polarization states The symbols H V R and L on the Poincar sphere display represent the polarization states described in Table 1 and are used throughout the PSGA control interface as well as the user manual Table 1 Special polarization states on Poincar sphere Parameters Horizontal linearly polarized light with polarization angle 0 with respect to the reference plane of the PSA 1 0 0 Vertical linearly polarized light with polarization angle 90 with respect to the reference plane of the PSA 0 1 0 Linearly polarized light with polarization angle 45 with respect to the reference plane of the PSA O R P VP 45 45 0 1 0 Linearly polarized light with polarization angle 45 with LH L H LH respect to the reference plane of the PSA R 0 0 1 Right hand circularly polarized light 0 0 1 Left hand circularly polarized light 5 2 Polarization State Generator PSG Module The PSGA 101A polarization measurement system includes an all solid state high speed 6 state polarization state generator PSG for Jones matrix Mueller matrix PMD and PDL measurement T
64. ollimator is supplied with the PSGA instrument Figure 12 It can be used with either FC APC or FC PC connectors The slot at the top of the FC adapter is for wide key connectors and the bottom slot is for narrow key connectors This FC adapter can easily be removed for free space measurements The diameter of a free space input light beam should be less than 1mm to ensure that the PSA s detector can collect all of the energy of the input light FC adaptor with collimator Figure 12 PSA module for free space and fiber guided light Document GP UM PSGA 101A 12 Page 20 of 86 5 3 1 PSA interface The PSA control data display interface Figure 13 Figure 14 consists of the following e PSA setup window accessed from Setup pull down menu e Poincar Sphere at the left of the main interface screen e Polarization ellipse at the top right of the main interface screen e PSA measurement parameter status box in the middle right of the main interface screen File Edit Setup Measurements Display Help PS A PSA DISABLE si x 0 6803 s2 x 0 6553 s3 x 0 3283 Power 1 352dBm 60 15 DOP lo 9955 0 Adjust PSG Power State LHP x Affm 11550 00 Sik 0 998 S2 0 070 S3 10 003 Left Right Up Down Home Clear ZIn ZOut Option Draw eseosecososososos Psa O PSG Trace Figure 13 PSA primary interface 5 3 2 PSA Setup The PSA has two operation modes high precisio
65. operating wavelength Outside operating wavelength range Error loading stored values Unable to store state Parameter setting error the start and end channels are not compatible with the step size Response to TLS SWP STA n command Command conflicts with another command already in operation TLA is not ready for output Command should be re sent Wavelength scan PMD measurement failure Requested command only applies in wavelength scan mode Current PMD measurement method is not wavelength scan method Wavelength Scan initialization failure Poincar Sphere Analysis PMD measurement failure Mueller Matrix PMD measurement failure Jones Matrix PMD measurement failure PDL measurement initialization failure Mueller Matrix PDL measurement failure Jones Matrix PDL measurement failure Measurement mode is not single wavelength mode Measurement mode is not wavelength scanning mode Incorrect wavelength setup Incorrect channel setup E72 Wavelength scan PMD measurement cannot use manual laser mode Document GP UM PSGA 101A 12 Page 83 of 86 Section 10 Technical Support and Factory Service Information 10 1 Technical Support General Photonics 1s committed to high quality standards and customer satisfaction For any questions regarding the quality and use of the PSGA 101A or future suggestions please contact General Photonics Corporation at 909 590 5473 telephone or 909 902 5536 fax or by e mail at info generalphotonics com Genera
66. output light or the PSA input light depending on whether PSG or PSA is selected in the Draw box under the sphere Click Point in the Option box under the sphere to display individual polarization states as colored points Click Trace to display a line connecting sequential points as shown in Figure 5 Points on the front half of the sphere are displayed in red while points on the rear half of the sphere are blue Document GP UM PSGA 101A 12 Page 14 of 86 Figure 5 Polarization traces For a clearer view of a particular section of the Poincar sphere click the Left Right Up or buttons to rotate the sphere about its horizontal or vertical axis The button erases all points or traces drawn on the sphere and zoom the sphere in and out respectively Polarization Ellipses top right of screen PSG PSA F PSA PSA Enable Figure 6 Polarization ellipses The polarization ellipse displays at the top right of the screen show 2 dimensional views of the polarization ellipse representations of the current polarization states of the polarization state generator output PSG and polarization state analyzer PSA input respectively The PSA ellipse only displays updates information when the PSA is enabled button at bottom of Figure 6 Document GP UM PSGA 101A 12 Page 15 of 86 PSA and PSG status boxes PSA PSA Enable Adjust PSG Power State LHP Atm 4550 00 Sil 0 993 Se
67. r panel of the PSGA Click the PCI information icon at the right bottom of the tool bar Figure 57 The resulting network information dialog box shows the current IP address and other network information The user can then input the PSGA s IP address in the Server IP edit box of the client program and establish the connection Figure 58 Once the connection is set up the user can use it to send commands to the PSGA On the PSGA end when a command is received a communication interface shows up and detailed information regarding the communication type command content and command response is returned Figure 59 File Setup Measurements Display Help x IP Information Internet Protocol TCP IP Address Type DHCP 192 168 0 20 Subnet Mask 255 255 255 0 0 1098 Default Gateway 192 168 0 1 o 0509 IP Address O NER START_ Azimuth 4 22 i 8 10 50 am Left Right Up Down Home Clear zin zout Draw Option psa PSG Point Trace Start Pw PolaWise ecnrtisi391 PER 39 24 Oi Figure 57 IP Setup Document GP UM PSGA 101A 12 Page 73 of 86 as Client Remote IP 192 168 0 5 Port 5000 Server IP 192 168 0 20 Connect Send Data PSA MTD Recv Data MTD 1 Disconnect Figure 58 TCP Client File Setup Measurements Display Help x Communication Information 192 168 0 5 GP PSGA101 192 168 0 5
68. range lo to 2 00 ps Laser Power lo dBm 40 20dEm Internal Tunable Laser Setup Internal Tunable Laser Setup Start Channel E 196 10 THz 1528 77 nm Start Channel Step Size E iy 0 25 THz Step Size Measurable DGD range io to 2 00 ps Step Number Fa iy lt 17 Step Number End Channel fs 191 85 THz 1562 64 nm End Channel a Internal laser b External laser or manually tuned laser Figure 19 Laser setup for PMD measurement Select Laser Type from the pull down menu Standard options are internal tunable laser Agilent HP laser Santec laser Ando laser and manually tuned laser this option allows the PSGA to be used with external lasers that cannot be controlled by the PSGA Control options for other tunable laser sources can be added by customer request If the internal laser is selected set the Start channel Step Size and Step number from the corresponding pull down menus in the Internal Tunable Laser Setup box Please refer to Section 8 for a detailed description of the optional internal tunable laser Note that the internal laser cannot be tuned continuously it can emit 89 discrete wavelengths channel 1 to channel 89 which match the 50GHz ITU grid in the C band After the Start channel Step Size and Step number for the internal tunable laser are set the frequencies and wavelengths corresponding to the selected values are calculated and displayed next to the paramet
69. rix of the DUT a reference matrix without the DUT in the light path must first be measured Connections for reference matrix measurement are shown in red Reference cable A For pigtailed DUT collimator B Free space measurement Figure 35 Setup for Mueller matrix measurement 6 4 3 Test procedure for Mueller matrix measurement e Select Mueller Matrix Measurement from the Measurements menu at the top of the main interface screen Figure 36 Document GP UM PSGA 101A 12 Page 49 of 86 Display Help PRIOJPOL Mueller Matrix PRIDSPDL Jones Matrix PRIOJPOL Jones Matrix Fast Mode PRIO Poincare Sphere Analysis PMD Wavelength Scanning POL Jones Matrix Single WL POL Mueller Matrix Single WL Mueller Matrix Measurement Beat Length Measurement Ww PSG PER Measurement Longterm Measurement Angle Measurement Figure 36 Mueller Matrix measurement selection e For a pigtailed DUT connect a reference patchcord between the PSG output and the PSA input to measure the reference matrix For free space applications use a pigtailed collimator to guide the light into the PSA with the adapter removed Click Reference to obtain the reference matrix Figure 37 e Connect a pigtailed DUT between the PSG output and the PSA input or place a free space optical component between the collimator output and the PSA Click DUT to begin the measurement The Mueller matrix of the DUT will be displayed in the
70. ropagating light is split into two local polarization modes which travel at different velocities The differential group delay DGD between the two orthogonally polarized modes causes pulse spreading in digital systems and distortion in analog systems General Photonics PSGA 101A_ polarization measurement system accurately characterizes various aspects of PMD including the wavelength dependence of the differential group delay DGD the principal states of polarization PSP the second order PMD etc The PSGA 101A supports four PMD measurement methods wavelength scanning Jones Matrix Eigenanalysis JME the generalized Mueller matrix method MMM and Poincar sphere analysis PS A fifth menu option is the fast Jones matrix method which provides quick measurement with slightly reduced accuracy for field applications The Jones matrix eigenanalysis and generalized Mueller matrix methods are the most generally accurate and is recommended for most cases The other methods are provided primarily for comparison and reference Document GP UM PSGA 101A 12 Page 24 of 86 PMD Phenomenon PMD coefficient SOPMDrms Table 2 Definitions and terms used in PMD measurement In an ideal circularly symmetric fiber light of any polarization state would propagate with the same velocity However in real fibers local stresses and imperfections in the circular symmetry cause propagating light to split into two local polarization modes which
71. ser output power changes of polarization state along the fiber between the laser and PSG etc during testing will produce significant measurement error Therefore accurate PDL measurement using the Mueller matrix method requires that the laser source be highly stable and that the fiber between the laser source and the PSG be firmly fixed in place If different polarization states with the same power pass through an optical device the relative angles between the input and the output polarization states will be different because of PDL If these angle changes are measured for at least three non degenerate polarization states then the PDL can be calculated using the Jones Matrix method Because the Jones matrix method is based on measurement of angle variations the measurement accuracy is insensitive to PSG output power fluctuations However any polarization disturbance in the fiber between the PSG and PSA will cause significant measurement error Therefore accurate PDL measurement using the Jones matrix method requires that the fiber between the PSG and PSA be fixed Because the Mueller matrix method MMM for PDL measurement is based on power measurement it can measure small PDL values with high accuracy but has relatively narrow dynamic range which is limited by the dynamic range of the detector The Jones matrix method JME is based on angle measurement so it provides high dynamic range but its resolution is limited by the angle measuremen
72. sh drives before powering on the instrument 7 Turn on the key for the internal tunable laser if applicable Note The key enables control of the laser It does not automatically turn the laser on Measurement functions involving wavelength scanning such as PMD PDL measurement or ER measurement will automatically turn on the laser when they are run However when using the laser with basic PSA functions or single wavelength PDL measurements it is necessary to manually turn on the laser To set the wavelength and turn the laser on select Internal TLS from the Setup menu to bring up the laser control screen see Section 8 8 On power up the WinCE system will start and will automatically load the measurement software After an initialization splash screen the display will show the interface pictured in Figure 4 9 Follow the instructions in Sections 5 9 for PSGA 101A control and measurements File Edit Setup Measurements Display Help PSA PSA Enable Oo 100 Adjust PSG Power Left Right up Down tome clear Zin zout Draw Option State LHP ACM 1550 00 PsA PSG Point Trace Si p993 S2 foizo 3 fo o0s Y Start owrolawise 5 12 PM Figure 4 PSGA 101A PolaWise software interface screen Document GP UM PSGA 101A 12 Page 13 of 86 Major features of the main software interface screen This is a quick reference for the main software interface Individual features and fu
73. start 2 pause 3 continue E00 OK E01 command error E13 parameter setting error the start and end channels are not compatible with the step size E14 commands conflict e g stop can be used only if a scan is in progress start can be used only if a scan is stopped or paused pause can be used only if a scan is in progress continue can be used only if a scan 1s paused E15 TLA is not ready for output Command should be re sent TLS SWP STA Returns the sweep status 0 Sweep is not running 1 Sweep in progress TLS SWP ssss TLS RST ssss next In manual mode advances to the next wavelength in the sequence E00 OK EO1 command error E14 commands conflict this command can only be used in manual sweep Resets laser source all settings are reset to default values TLS WAV nn Returns the wavelength of the channel nn Pe TLS FRQ nn Returns the frequency of the channel nn Lf l TLS CHN MAX Returns the number of the highest available channel Document GP UM PSGA 101A 12 Page 82 of 86 9 9 Error Definitions E00 No error State OK Undefined Command Missing or incorrect parameter Invalid syntax found in command string string of characters too long gt buffer limit parameter has too many digits after the decimal point parameter outside the allowed range Failed Self Test Light power too high Light power too low Incorrect
74. t polarization state is close to orthogonal to alignment polarizer axis Status Report Commands Report Command Returned Value PSG WAV Returns PSG wavelength WAY fffF fFF unit nm E01 Example WAV 1550 00 PSG STA PSG RHC LHC 0 90 45 45 SCAN etc PSG STK Returns Stokes parameters for STK sf fffisffffist fff E01 PSG output polarization state Example STK 1 000 0 003 0 002 PSG DWL Returns dwell time setting Example PSG DWL 1 0 E01 unit s Document GP UM PSGA 101A 12 Page 75 of 86 9 4 PSA GPIB Ethernet Commands Setup Commands Control Command PSA ENA lt setting gt PSA enable disable E00 lt setting gt ON OFF E02 if the lt setting gt Example PSA ENA ON parameter 1s omitted or is something other than ON or OFF PSA MTD n Sets the PSA measurement mode E00 PSA MTD 0 PSA MTD 1 E02 ifn is omitted or is 0 high speed 1 high precision Default 1 something other than 0 or 1 PSA WAY ffff ff Sets PSA wavelength all values in nm E00 E01 E02 E06 Example PSA WAV 1500 00 to set wavelength to 1500 00 nm Range 1440 1620 Status Report Commands Error enabled or disabled PSA STK Returns the current STK sf fffisf fff sf fff E08 E09 measured Stokes parameters POW ff fffff MW PSA PKG dBm mw Returns Power and PKG sff fffff DBM MW E08 E09 Stokes parameters sfi fffiisfffisf fff sf fff Format Power s1 s2 s3 DOP light of input light of input light p
75. t resolution of the PSA Therefore for maximum accuracy the MMM should be used for measurement of small PDL values and the JME for measurement of high PDL values Document GP UM PSGA 101A 12 Page 38 of 86 6 2 2 Setup for PDL measurement The optical connections used for PDL measurement are the same as those for PMD measurement as shown in Figure 23 If using the internal tunable laser make sure that the laser key is turned to the on position before beginning measurement A Using internal TLA B Using External TLS Figure 23 Setup for PDL measurement Document GP UM PSGA 101A 12 Page 39 of 86 6 2 3 PDL Measurement procedure From the Measurements pull down menu select the desired measurement method For single wavelength measurements PDL Jones Matrix Single WL or PDL Mueller Matrix Single WL For PMD PDL vs wavelength measurements PMD PDL Jones Matrix PMD PDL Jones Matrix Fast Mode or PMD PDL Mueller Matrix Figure 24 Display Help Display Help PROVPOL Mueller Matrix PRMIDVPOL Mueller Matrix PMIDIPDLi Jones Matrix PMOPDL Jones Matrix PROVPDL Jones Matrix Fast Mode PMDVPDL Jones Matrix Fast Mode PRIO Poincare Sohere Analysis PMO Poincare Sphere Analysis PMD Wavelength Scanning PMO Wavelength Scanning POL Jones Matrix Single WWL PDL Jones Matrix Single WL POL Mueller Matrix Single WL POL Mueller Matrix Single YL Mueller Matris Measurement Mue
76. the number of wavelengths channels included in the measurement PMD DGD nnnn Returns the nnnnth measured DGD WL ffff ff DGD fff fff E06 Range nnnn lt mmmm 1 Note returned is the see PMD NUM corresponding to the nnnnth measured DGD PMD TWO nnnn Returns the nnnnth measured WL ffff ff SODGD fff fff E06 second order PMD Note A returned is the A Range nnnn lt mmmm 2 corresponding to the nnnnth see PMD NUM measured SODGD PMD PSP nnnn Returns the nnnnth measured PSP WL ffff ff f ffff fff f fff E06 Range nnnn lt mmmm 1 A and Stokes parameters for see PMD NUM nnnnth PSP measured wavelength range measured wavelength range PMD DEV Returns the standard deviation of fff fff DGD over measured wavelength range measured wavelength range measured wavelength range PMD TWO AVG Returns the RMS second order FEEF fff PMD over measured wavelength range PMD MTD Queries the PMD measurement 0 Jones matrix eigenanalysis method 1 PSA method 2 Mueller Matrix 3 Wavelength scanning PMD PDL nnnn Returns the nnnnth measured PDL WL ffff ff PDL fff fff E06 Range nnnn lt mmmm Note returned is the see PMD NUM corresponding to the nnnnth measured PDL PMD PDL AVG Returns the average PDL over FEEF fff measured wavelength range PMD PDL DEV Returns the standard deviation of FEEF fff PDL over measured wavelength range PMD PDL MAX Returns the MAX PDL over FEEF
77. tionship is 6 4 AA betweenpeaks n m _ 6 5 ps nm ET 6 5 AA betweenpeaks n m Document GP UM PSGA 101A 12 Page 29 of 86 Delta parameter selection Once a wavelength scanning response has been measured it must be analyzed to identify and count peaks and valleys extrema The parameter Delta specifies the threshold value of magnitude change used to differentiate a peak from an adjacent valley For maximum accuracy it must be small enough to differentiate legitimate peaks and valleys and large enough that fluctuations from noise are not identified as extrema The default value of this parameter is 0 05 Calculation method selection Two methods can be used for PMD calculation from the scanning data 1 For the First to Last method a in Equation 6 3 is the wavelength of the first extremum and A is the wavelength of the last extremum 11 For the Full Scan method A in Equation 6 3 is the start wavelength of the scan and A is the end wavelength of the scan The Full scan method should be used for the measurement of single mode fiber for optical components or PM fiber the First to Last method can give better accuracy Document GP UM PSGA I101A 12 Page 30 of 86 6 1 4 Setup for PMD measurement The recommended PMD measurement setups using the PSGA 101A s internal tunable laser TLA and an external tunable light source TLS are shown in Figure 17a and b respecti
78. travel at different velocities This effect is known as the PMD phenomenon The resulting differential group delay between the two orthogonally polarized modes causes pulse spreading in digital systems and distortions in analog systems The principal states of polarization PSPs are the two orthogonal input states of polarization for which output polarizations do not vary when the optical frequency changes slightly These two PSPs are also the polarization states with the maximum fast PSP and minimum slow PSP values of group velocity In the PSGA interface PSP denotes the fast PSP Differential group delay DGD is the difference in delay between the slow PSP and fast PSP at a specified wavelength It is given in units of picoseconds ps Polarization mode dispersion PMD 1s defined as the linear average or the root mean square RMS of the DGD values over a given wavelength range at a certain time or over a given time window at a certain wavelength The PMD coefficient is the PMD value normalized to the measurement length For random mode coupling the PMD coefficient is the PMD value PMDayg or PMDrms divided by the square root of the length L with units of ps Vkm For negligible mode coupling the PMD coefficient is the PMD value PMDaye or PMDems divided by the length L with units of ps km The second order PMD SOPMD at a given frequency is defined as 9 soPMD oj 2O _ ie a d where Q is the pol
79. up dialog box will pop up Figure 26 Select the laser type from the pull down menu Available options include internal tunable laser Agilent HP laser Santec laser Ando laser and manually tuned laser Laser Setup Laser Type d Agilent HP Laser gilent 7 j Wavelength Operation Scanning Wavelength External Laser Setup Start Single wavelength isso nm End wavelength 1560 nm Step in nm 0 001 100nm Measurable DGD range o p Laser Power booo dBm 40 20d6rm Internal Tunable Laser Setup Start Channel h Ed 196 10 THz 1528 77 nm Step Size 5 a fast Measurable DGD range foto200 ps Step Number far x lt 17 End Channel be 191 85 THz 1562 64 nm Figure 26 Wavelength scanning Laser setup for PDL measurement If internal laser is selected the Internal Tunable Laser Setup box will be enabled Set the Start channel channel 1 89 Step Size number of channels in each step and Step number number of steps in the scan from the pull down menus Figure 26 After the scan parameters are set the corresponding frequencies and wavelengths are calculated and displayed in the boxes next to the parameters Note The sum of Start_channel Step_size Step_number must be less than 89 Document GP UM PSGA 101A 12 Page 41 of 86 If the external or manually tuned laser is selected set the Start wavelength End wavelength Wavelength step size and
80. urement interface Figure 41 Since the beat length is calculated from measured DGD the laser scan parameters should be chosen according to the expected DGD of the fiber under test Document GP UM PSGA 101A 12 Page 55 of 86 Dispersion Equation Coefficients ul 0 407943 B3 0 597479 C1 o 0046791 Le 0 0135 121 C3 97 934 Default Measurement Fiber Length p m SIN PMD ii 111 ps Beat Length 4 727 mm i 1545 707 nm Beat Length 4 006 mm T 1310 nm B 0 696166 B2 Figure 41 Beat Length Measurement Interface e Input the length and serial number of the fiber under test Note that the length of fiber that can be measured will be limited by the DGD measurement range corresponding to the wavelength range of the laser source 10 ps for the internal tunable laser Click Start to begin measurement The PMD of the fiber and the beat length at the center wavelength of the scanning range will be calculated and displayed The approximate beat length at 1310nm is also calculated using equation 6 18 Once a measurement is completed the data can be saved by clicking the Save button The user will be prompted to input a file name and location for the saved data e The default dispersion equation 6 16 coefficients used for the calculation are those of fused silica glass Users can change save and load sets of dispersion coefficients for different materials to more closely match the fiber under test Document GP
81. using the A and TLS buttons The laser and wavelength settings can also be manually set using the and TLS keys Document GP UM PSGA 101A 12 Page 62 of 86 7 9 PDL measurement Note Only single wavelength PDL measurements can be performed using front panel control A B a Wavelength _ a 1550 00 nm Figure 48 PDL measurement front panel control sequence e Check that the laser key above the main power button is in the on position e When the key is pressed the wavelength selection screen Figure 48A is displayed e Use the arrow keys to set the wavelength then press to proceed to the measurement interface Figure 48B e Use the arrow keys to select the number of measurements to be averaged within the range of 1 99 e Move cursor to Start using the right arrow key then press to start the measurement e After the measurement is completed the PDL value will be displayed If any error is found during testing the test will be terminated and the errors will be shown Document GP UM PSGA 101A 12 Page 63 of 86 7 6 PMD measurement laser selection 1 Internal TLS 2 Agilent laser 3 Santec laser 4 Ando laser Figure 49 Laser selection screens The TLS key is used to select the laser source used for PMD measurement e Goto TLS setup interface by pressing the key Figure 49 e Use up and down arrow keys A V to select the desired laser source for PMD measurement default is
82. velength accuracy polarimeter accuracy and the repeatability of the stimulus polarizations Larger wavelength steps generally provide better accuracy However in order to unambiguously measure the polarization change produced by the step the rotation of the output state about the principal state axis on the Poincar sphere produced by any single wavelength step must not exceed 180 degrees In the region of 1550nm this alias limit limits the range of PMD values that can be measured with a given wavelength step size as follows At ps AA lt 4 0 ps nm external lasers 6 1 or Ar ps Ach lt 10ps internal laser 6 2 where AA is the wavelength step for external lasers and Ach is the step size of ITU grid channels for the internal tunable laser with a minimum wavelength step of 0 4 nm For example when AA is set to Inm the maximum DGD that the PSGA 101A can measure is 4 ps Similarly when Ach is set to 1 the minimum step the maximum DGD that the PSGA 101A can measure is 10ps In general the user should select the largest step size that satisfies these equations for the expected range of the PMD to be measured Document GP UM PSGA 101A 12 Page 28 of 86 6 1 3 PMD measurement principle for wavelength scanning method The setup for the wavelength scanning method is the same as for the other methods The difference is that the PSG maintains only one output polarization state during wavelength scanning The resulting SOP
83. velength or by changes in the fiber s optical path length The PSGA s measurement method options are based on these two principles In the Stretch Heat method the input wavelength remains constant and the user stretches or heats the PM fiber to cause polarization rotation In the scan method the tunable laser is used to scan the input wavelength while the PM fiber is left unchanged Select the desired method from the Methods pull down menu in the PER measurement area in the bottom right corner of the main screen Figure 32 Stretch Heat method e Press PER START to begin the measurement The PSGA will begin to draw the PM fiber s output polarization state on the Poincar sphere e Gently stretch or heat a section of fiber near the PSA input port until at least half a circle has been traced out on the Poincar sphere Hold the fiber straight while it is being stretched or heated e Once a sufficient section of a circle has been traced out click the PER STOP button to calculate the PER and the key alignment angle Figure 33 A Scan Method e Click PER START to begin measurement The internal tunable laser will scan the wavelength using the parameters set up from the PER laser setup screen as described above After the scan is finished the PER azimuth angle with respect to Document GP UM PSGA 101A 12 Page 46 of 86 the horizontal direction and PM fiber axis to which the light is aligned slow fast are calculat
84. vely All fiber used in the measurement should be firmly fixed in place Any fiber movement will affect the polarization states and reduce the measurement accuracy If using the internal tunable laser make sure that the laser key is turned to the on position GPIB B Using External TLS Figure 17 PMD measurement setups 6 1 5 PMD measurement procedures for JME MMM and PS methods Select the preferred measurement method from the Measurement menu Figure 18 Display Help PME FOL Mueller Matrix PRIDVPDOL Jones Matrix PMO POL Jones Matrix Fast Mode PMD Poincare Sphere Analysis PMID Wavelength Scanning PDL Jones Matrix Single WL POL Mueller Matrix Single WL Mueller Matrix Measurement Beat Length Measurement PSG PER Measurement Longterm Measurement Angle Measurement Figure 18 PMD measurement method selection Document GP UM PSGA 101A 12 Page 31 of 86 After the measurement method is selected a tunable laser setup dialog window Figure 19 pops up Laser Setup Laser Setup Laser Type Internal Tunable Laser Laser Type Agilent HP Laser Wavelength Operation Scanning Wavelength Wavelength Operation Scanning Wavelength External Laser Setup External Laser Setup Start Single wavelength ci Start Single wavelength 1550 Am End wavelength End wavelength 1560 nm Step nm 0 001 100n0m Step E nm 0 001 100nm Measurable DGD range ps Measurable DGD
85. version of the instrument allows measurement of PMD values up to 10 ps The PSGA can also be used with external tunable lasers for measurement of PMD values outside this range The PSGA 101A can be remote controlled through industry standard GPIB or ETHERNET connections The ETHERNET capability enables customers to measure the polarization properties of existing links at different network locations Document GP UM PSGA 101A 12 Page 7 of 86 Section 3 Feature Description 3 1 Optical Features The PSGA 101A system has four fiber adapters for optical beam inputs and outputs as marked on the front panel Figure 1 The far left connector is the output from the optional internal tunable laser The two middle connectors are the input to connect to either the internal laser source or an external source and output of the polarization state generator PSG The far right connector is the input to the polarization state analyzer PSA The recommended default connector type for the internal tunable laser output and PSG input output is FC PC although other connector types are available by customer request The PSA input is free space and can accept either FC APC or FC PC connectors FC APC is recommended to reduce back reflection from the connector Figure 1 PSGA 101A front panel The laser and PSG connectors are universal connector interfaces UCI which feature a male type adapter top piece that can be removed for direct access t
86. vs wavelength curves measured by the PSA contain many peaks and valleys By counting the number of these extrema the average DGD PMD can be calculated Wavelength scanning method data acquisition and analysis PSG output is set to one of the six non degenerate states The TLS is tuned to wavelength A PSA measures the SOP S1 S2 S3 of DUT output The process is repeated to obtain S A S2 A and S3 A curves PMD 1s calculated using the following formula KN AA gt 6 3 A A c oe where A and A are the positions of the first and last extrema of S A k is a mode coupling constant that equals 1 0 in the absence of strong mode coupling and 0 824 in the limit of strong mode coupling and N is the number of peaks and valleys measured over the frequency range from A to Ap PMD Wavelength range selection for wavelength scanning method The wavelength range over which the PMD measurement is performed should be great enough to produce a statistically significant number of extrema For optical components without mode coupling a basic measurement can be based on a single cycle of amplitude change or even a single peak and valley pair Near 1550nm the wavelength change required to span two peaks for a given component is approximated by _ 7 8 ps nm AT ps A component with a Ips average differential group delay produces peaks which are spaced an average of 7 8 nm apart For random mode coupled devices the rela

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