User Guide
Contents
1. 00 selects Poincar sphere live view 01 selects Poincar sphere memory view 10 selects Oscilloscope view 11 tbd 512 187 0 R W 1 enables automatic Poincar sphere refresh 512 188 15 0 RAW Automatic Poincar sphere refresh period in milliseconds 16 bit unsigned 512 189 15 0 W Any write transaction to this register clears the Poincar sphere on the connected monitor 512 204 11 0 RAW HDMI frame buffer pixel row 512 205 9 0 RW HDMI frame buffer pixel column 512 206 15 0 R HDMI frame buffer pixel data code 512 207 0 RW 0 freezes HDMI frame buffer Novopiel 9 of 28 PM1000_UG_0_2 5 n02 doc Operation of the instrument via front control panel The polarimeter firmware provides a cyclic menu the keywords of which are shown on the OLED display The menu structure is Optical frequency Averaging time ATE Normalization mode Sphere Oscilloscope Rotate H Zoom Rotate V Shift Memory exponent ME Reset dark current Factory User calibration The control buttons UP and DOWN let you to navigate through the menu The control buttons LEFT and RIGHT change a selected setting or value Reset dark current Especially at low input powers recalibration of the 4 photodetector s dark currents can improve measurement accuracy Use the UP DOWN buttons to navigate through the menu until Reset dark current is displayed Disable any optical in2. gt Connect PM1000 v Status Connected Subsequently you can launch further instances of the GUI and connect them to further instruments Setting the optical frequency Type the optical frequency in THz with up to two positions after decimal point into the field besides Frequency and press Enter or tune the frequency with the up and down buttons Novoptel 14 of 28 PM1000_UG_0_2_5_n02 doc Outside the calibrated frequency range the polarimeter matrix will be extrapolated Measurements in the extrapolated range will be less accurate than in the calibrated range If a frequency in the extrapolated range is selected a warning message will be displayed Frequency THz 192 00 Setting the averaging time exponent ATE ATE 05 100 0MS s Type any valid ATE value between O and 20 into the box and press Enter or adjust the ATE with the up and down buttons The resulting conversion rate is displayed at the right of the box Selection of a normalization mode Stokes Vector Normalization Non normalized Standard norm Exact norm Select the desired normalization mode from the drop down list Save a screenshot A screenshot of the current picture that is displayed at the monitor connected to the PM1000 can be saved on the PC in png format Device Tools Help _ i Save Screenshot i Status Save Data Full Memory Block s Frequency Select Data File Type gt Non normalized SOP Power Refer
3. DUT measurement has finished the Mueller matrix and the calculated PDL are displayed Novoptel 22 of 28 PM1000_UG_0_2 5 n02 doc PM_GUI Ss Mueller Matrix 0 544536 0 16031 0 0541644 0 0247766 0 150463 0 407883 0 163003 0 311404 0 0812281 0 312525 0 0801227 0 412042 0 00316103 0 170092 0 487049 0 0336801 Mean Loss 2 640 dB PDL 2 823 dB Using Matlab to analyze stored data As described in the sections above the GUI allows storing the measured data in form of text or binary files These files can be opened for further investigation by Matlab in an easy way The files start with a header that contains the measurement meta data The header is formatted in such a way that it can directly be evaluated by Matlab after the hash signs are removed Timestamp 2015 07 21 16 22 16 698 ATE 9 SamplePeriod_ns 5120 ME 10 Normalization 0 CyclicRecording 1 TriggerConfiguration 828 TriggerThreshold 2621 DatalName Power PowerLeftShift 5 In binary files the length of the header is given by the variable headerlength which itself stands at the beginning of the header It is at least 256 This means that the first 256 bytes of the file or more if headerlength is larger represent text in ASCII format which should be evaluated to get the measurement meta data The measurement data starts after the header at byte number 256 if header bytes are counted from 0 to 255 The
4. cases this register will represent the data output of a memory After sending this packet burst transfer will start Beginning with the start value the address register will be incremented until it reaches the stop value After every step the data appearing in the read address register will be transferred to the host Novoptel 27 of 28 PM1000 UG O 2 5 n02 doc Operation of the instrument using other programs The USB vendor http www ftdichip com Support Knowledgebase index html provides examples for USB access using other programs for example LabVIEW A rudimental example of a LabVIEW VI virtual instrument is available from Novoptel upon request Firmware upgrade Via the JTAG port the user can upgrade the firmware if ever needed The schematic and timing of the JTAG port correspond to that detailed in Spartan 6 FPGA Configuration User Guide UG380 v2 6 June 20 2014 from Xilinx www xilinx com Acronyms ATE Averaging time exponent DOP Degree of polarization DUT Device under test DVI Digital visual interface FPGA Field programmable gate array GUI Graphical user interface HDMI High definition multimedia interface LSB Least significant bit JTAG Joint test action group ME Memory exponent MSB Most significant bit PC Personal computer PDL Polarization dependent loss SOP State of polarization SPI Serial peripheral interface USB Universal serial bus Novopiel 28 of 28 PM1000_UG_0_2 5 n02 doc
5. register address A is sent using 3 bytes each containing the ASCll character of the hexadecimal numbers 0 to F which represents the 4 bit nibble The character of the most Novoptel 26 of 28 PM1000_UG_0_2 5 n02 doc significant nibble is sent first The 16 bit data which should be written into the register is sent with 4 bytes using the same coding as the register address Reading data from a register requires the host to send a request data packet to the instrument The packet starts with the ASCll character R followed by the register address coded the same way as in write data packets Send request data packet Lm aa am am o ur oe or or After receiving the request data packet the instrument sends the requested data packet to the host DOSE Burst transfer To increase transfer speed consecutive addresses of an internal memory can be transferred at once Additional packets are defined for this purpose Send Set burst address register packet GERRODODEI The data D is the address of the register that will be incremented during burst transfer In most cases this register will represent the read address of a memory Send Set start value packet The data D is the start value of the counting Send Set stop value packet The data D is the stop value of the counting Send Set read address packet The data D is the address of a register that contains the data to be sent during burst transfer In most
6. the instructions of the installation dialogue If not found on the PC Microsoft NET Framework 4 5 will be installed during installation of the GUI In addition the Visual Basic Power Packs will be required to be installed They can be downloaded using the following link http go microsoft com fwlink LinkID 145727 amp clcid 0x804 Pe N Novoptel PM500 PM1000 Polarimeter Interface oa Device Tools Help Status Connected Memory Triggering Gating Intemal Trigger Calibration Device T est Stokes P X i i its 4 S 9 aut Frequency THz 193 40 okes Power Power in pw fractional bits auto ME 18 2 256 KiS Block Memory Recording Time 1 4 min Trigger Event Recording ATE 15 3 1 kS s Start sa Naa Recording Multiple Events 256 Events Stokes Vector Normalization SS Auto Reactivate Standard norm v Events 000 Auto Save TO Times Fill HDD Sub Dirs E Show Sphere Live E Show Sphere Memory Show Scope Memory Close The software launches automatically after installation If you want to launch the software later manually select Programs Novoptel PM_GUI from the Windows Start Menu Basic operation Selecting one of the attached instruments If you have attached only one Novoptel polarimeter the GUI automatically selects this one If you have attached more than one instrument select the desired one from the drop down list in the menu strip Device
7. User Guide Novoptel PM1000 Polarimeter Novoptel Pe ij amp PM1000 Polarimeter pa Novoptel GmbH EIM E Warburger Str 100 33098 Paderborn Germany www novoptel com Revision history Version Date Remarks Author 0 2 1 26 01 2015 Draft version B Koch 0 2 2 27 02 2015 Register and operation description updated B Koch 0 2 3 04 03 2015 Operation description updated B Koch 0 2 4 11 03 2015 Description of measurement data files B Koch 0 2 5 21 07 2015 Description of PDL measurement B Koch Table of contents IntrodUCUON pesien E A AEE SN E SR 4 Rear panelei eai R a E AEAEE a dO 4 EXE WTA 14 9 1 10 o ARRAIS 4 FuUncamental PMI000conigilalioi ai 5 Register DOS CRIANCA eg a aa 5 Operation of the instrument via front control panel 10 Reset dark CURE urina cnn ceetiervanwapacGreeaantiioasiaesetdcoanGeieewened beers deme Ghigiterdianmineineds 10 Sphere oscilloscope mccain 10 Factory User calibration scces ondscracasarsvetanstwsdeatd niseeae samen ned iaiirvoereackuceeauenmiceinmnecoiemnetnens 10 Connecting the instrument to a PC via USB 11 Installing the USB Ave qua apatia aU O a 11 Connecting the instrument rai rl 11 Interfacing the instrument via SPl cercar neeeraerananda 12 Serial interface SPI commands rica 12 Serial interface SPIIMINO ira 12 Operation of the instrument via graphical user interfaCe in 14 Installin
8. addresses have an offset of 512 This allows a Novoptel PM1000 polarimeter and EPS1000 polarization scrambler transformer to be connected to a shared single SPI port All undefined registers are reserved and should not be written into Register Name Bit s Read Function address Write 512 0 ALM Internal alarm code The alarm can be cleared by writing O to this register This is successful only if the alarm condition is no longer present 0 R W Alarm condition present 1 R W Optical input over range 2 R W Optical input under range 4 R W Critical board temperature 512 1 ATE 9 0 R W Averaging time exponent ATE integer range 0 to Novoptel 5 of 28 PM1000 UG 0 2 5 n02 doc 20 512 2 PCI 15 0 R Photocurrent 1 16 bit unsigned averaged according to ATE 512 3 PC2 15 0 R Photocurrent 2 16 bit unsigned averaged according to ATE 512 4 PC3 15 0 R Photocurrent 3 16 bit unsigned averaged according to ATE 512 5 PC4 15 0 R Photocurrent 4 16 bit unsigned averaged according to ATE 512 6 LPC2 15 0 R Latched copy of photocurrent 2 updated on any read of PC1 512 7 LPC3 15 0 R Latched copy of photocurrent 3 updated on any read of PC1 512 8 LPC4 15 0 R Latched copy of photocurrent 4 updated on any read of PC1 512 9 PCFP 15 0 R Floating point position of photocurrent 1 to 4 updated on any read of PC1 512 10 SOuWU 15 0 R Input powe
9. ained data oe This is to plot the stokes parameters loaded from a Novoptel PM1000 polarimeter GUI version 1 0 1 8 Copyright 2015 Benjamin Koch Novoptel GmbH oe oe function pm1000plot filename open the data file FID fopen filename get the meta data C textscan FID s Delimiter load information from meta data if length C 1 gt 0 for ii l length C 1 try eval C 1 ii catch err disp sprintf ERROR Unknown co end end end ss C 1 ii get the stokes values NN textscan FID Sf f f f close the data file fclose FID for ii 1 4 N ii NN ii end remove offset from stokes parameters 1 3 N 2 4 N 2 4 2 15 plot the data x l length N 1 SamplePeriod_ns 10 9 X Axis in seconds Sx l length N 1 X Axis as samples plot x N 2 15 att x NESS ir amp N 803 2 15 5 x N d 2 215 Vig Igy legend DatalName Stokes 1 Stokes 2 Stokes 3 xlabel Seconds Read data from binary files The following Matlab function will open a binary file and plot the contained data de This is to plot the stokes parameters loaded from a Novoptel PM1000 polarimeter GUI version 1 0 1 8 Copyright 2015 Benjamin Koch Novoptel GmbH ole de function pml000plotbinary filename open the data file FID fopen filename get the header length mimimum 256 bytes C fread FID 256 uint8 headerstrings strsp
10. ash to be able to access it without GUI Memory Triggering Gating Internal Trigger Calibration Device 1 Test Factory Calibration User Calibration User Calibration Options Save from PM500 PM1000 to PC File Load from PC File to PM500 PM1000 Rewrite PM500 PM1000 Flash Memory Device Test If available a Novoptel polarization scrambler transformer e g EPS1000 or EPX1000 can be controlled by the GUI to measure polarization dependent loss PDL and the Mueller matrix of a connected device under test Memory Triggering Gating Internal Trigger Calibration Device Test Connect Novoptel Polarization Scrambler Transformer EPS DEMO Refresh PDL by Extinction Method Run PDL Measurement PDL by Mueller Matrix Nr of SOPs 6 9 14 Run Ref Meas Run DUT Meas PDL by Extinction Method If PDL is measured by Extinction Method the polarization scrambler transformer is driven to obtain the polarization states where minimum and maximum transmissions are reached From minimum and maximum transmission PDL can be calculated Novoptel 21 of 28 PM1000_UG_0_2_5_n02 doc P A PDL Measurement Extinction Method 5 fo IE Min Power 000 00 pw UD 0000 u02 0000 Max Power 000 00 pw U11 0000 U12 0000 Cur Power 000 00 pw U21 0000 U22 0000 U31 0000 U32 0000 Step 200 ATE1 17 U41 0000 U42 0000 EE o USI 0000 US2 0000 Ste
11. e stop address in the selected memory block bits 25 16 512 82 9 0 R W Maximum number of memory blocks in automatic retrigger mode Default is 512 512 86 0 R W Define reference for internal trigger signal 0 External Stokes vector 1 Internal delayed Stokes vector 6 1 RAW Number of clock cycles for Stokes vector delay 10 7 R W Exponent for clock division of Stokes vector delay 512 87 15 0 R W Stokes parameter 1 of external Stokes vector reference 15 fractional bits Offset 2 512 88 15 0 R W Stokes parameter 2 of external Stokes vector reference 15 fractional bits Offset 2 512 89 15 0 R W Stokes parameter 3 of external Stokes vector reference 15 fractional bits Offset 2 512 90 15 0 R Current internal trigger signal 512 91 15 0 R W Trigger threshold for internal trigger signal 512 92 0 RW 1 enables internal triggering 1 R W_ 1 enables internal gating 2 RAW Internal triggering gating 0 Active high rising edge 1 Active low falling edge 3 R W 1 enables external triggering Novoptel 8 of 28 PM1000_UG_0_2_5_n02 doc 4 RW 1 enable external gating 5 RAW External triggering gating 0 Active high rising edge 1 Active low falling edge 512 93 0 R W When set to 0 this bit will become 1 after the next trigger event 512 95 3 0 R W Undersam
12. ector Standard Normalization 15 fractional bits Offset 2 512 27 S3St 15 0 R S3 of Stokes vector Standard Normalization 15 fractional bits Offset 2 512 28 LS1St 15 0 R Latched copy of S1St updated on any read of DOPSt Novoptel 6 of 28 PM1000 UG 0 2 5 n02 doc 512 29 LS2St 15 0 R Latched copy of S2St updated on any read of DOPSt 512 30 LS3St 15 0 R Latched copy of S3St updated on any read of DOPSt 512 31 DOPEx 15 0 R Degree of polarization DOP 16 bit unsigned 15 fractional bits 512 32 S1Ex 15 0 R S1 of Stokes vector Exact Normalization 15 fractional bits Offset 2 512 33 S2Ex 15 0 R S2 of Stokes vector Exact Normalization 15 fractional bits Offset 2 512 34 S3Ex 15 0 R S3 of Stokes vector Exact Normalization 15 fractional bits Offset 2 512 35 LS1Ex 15 0 R Latched copy of S1Ex updated on any read of DOPEx 512 36 LS2Ex 15 0 R Latched copy of S2Ex updated on any read of DOPEx 512 37 LS3Ex 15 0 R Latched copy of S3Ex updated on any read of DOPEx 512 38 EPow 15 0 RAW Reference power level in uW for non normalized Stokes vectors to reach a length of 1 512 39 S1Nn 15 0 R S1 of Stokes vector Non normalized 15 fractional bits Offset 2 512 40 S2Nn 15 0 R S2 of Stokes vector Non normalized 15 fractional bits Offset 2 512 41 S3Nn 15 0 R S3 of Stokes vector Non nor
13. ence j ATE 11 Log File Directory LAR Rec Delay After Alarm Condition 5 b Sil i YT To do so select Tools gt Save Screenshot from the menu strip and select a target folder on your hard disk Poincar sphere display At a reduced sampling rate of 1 to 2 kHz depending on processing power of the host PC the actual SOP samples can be displayed in the GUI A new window is opened after pressing Show Sphere Live Show Sphere Live Novoptel 15 of 28 PM1000_UG_0_2_5_n02 doc The sphere window can be resized by moving the window corners with the mouse Power degree of polarization DOP and the three Stokes parameters are displayed as color bars and text N Novoptel PM500 PM1000 Sphere o ia Novoptel PM500 PM1000 Power 1 128 mW 0 53 dBm DOP 1 001 Ss Stokes 1 0 041 I Stokes 2 0 289 Stokes 3 0 957 pro Normalization mode Standard The orientation of the Poincar sphere can be changed by moving the mouse with left button pressed In the upper right corner a pause play symbol can be pressed to freeze release the display The endless plotting of SOPs can be paused by clicking on the Pause sign which appears when moving the mouse into the upper right corner The sphere window can also be used to display SOP samples that have previously been stored in the PM1000 internal memory This is done by pressing Show Sphere Memory instead of Show Sphere Live Af
14. ents depends on the memory block size defined by ME At ME up to 17 the maximum is 512 At larger ME the maximum is 2 6ME This means that at an ME of 26 whole memory as one block only one event can be recorded If multiple events have been recorded the 700 s gt Save Data option from the menu strip will store each event in a separate file The Save data screen span option in the scope window will only store the event that is currently displayed Auto reactivated recording and storing For automated measurements the GUI allows to automatically store the measurement data in a file and re activate the measurement The number of activations generated in this mode can be defined between 1 and 1000 If multiple events are recorded during each activation multiple files will be stored after each recording If the checkbox Fill HDD is activated the number of files created is only limited by disk space Even if there is disk space available Windows sometimes blocks file creation in directories that already contain many ten thousand files If the checkbox Sub Dirs is activated the GUI will create a new directory at the beginning of a measurement and every time the current directory is blocked Triggering and gating The Triggering Gating tab of the GUI allows to enable triggering or gating of the memory recording Triggering means that the cyclic measurement process is stopped after recording of post trigger samples Gating means that the rec
15. eter so that it can be accessed through the polarimeter menu without a PC Connecting the instrument to a PC via USB The instrument communicates by a USB IC FT232H from FTDI Future Technology Devices International Limited http www ftdichip com The Novoptel PM1000 Graphical User Interface GUI is compiled on a Microsoft Windows 7 64 Bit system Installing the USB driver Execute the installation program of the provided USB driver CDM v2 10 00 WHQL Certified exe You will find more detailed information about the driver at http www ftdichip com Support Documents InstallGuides htm Connecting the instrument After the driver is installed successfully connect PC and instrument using the provided USB cable Wait until Windows has recognized the USB device and shown an acknowledgement message Power the instrument with the provided power supply and switch it on Novoptel 11 of 28 PM1000_UG_0_2 5 n02 doc Interfacing the instrument via SPI All internal registers can also accessed by SPI The SPI interface allows communication with much lower latency than USB The SPI connector at the backside of the device provides the following connection Connector notch Transmission starts with falling edge of CS and ends with rising edge of CS After falling edge of CS the command is transmitted SDI is sampled with rising edge of SCK Maximum SCK frequency is 500 kHz Command and data word length is 16 bit each MSB of command and da
16. from http Awww novoptel de Home Downloads Matlab Support Files zip Access the USB driver Matlab needs a header file like ftd2xx h from FTDI to access the driver Novoptel provides the header version matftd2xx h in which the data types are modified to become compatible with current Matlab versions You will find help about communicating to a driver at http www mathworks com help techdoc ref loadlibrary html The different functions of the driver can be seen from the header file Information about each function is provided at http www ftdichip com Support Knowledgebase index html Example Matlab programs for USB data transfer are available from Novoptel upon request USB Settings The following settings have to be applied within Matlab or other programs to enable USB communication Baud Rate 230400 baud Word Length 8 Bits Stop Bits 1 Bit Parity 0 Bit To speed up sequential read and write operations we recommend setting USB Latency Timer 2 ms Transfer protocol The instrument is controlled by reading from and writing to USB registers The register address line is 12 bits wide while each register stores 16 bits All communication is initiated by the USB host e g the Matlab program Writing to a register uses a 9 byte data packet Each byte represents an ASCII coded character The packet starts with the ASCII character W and ends with the ASClI code for carriage return Send write data packet The 12 bit
17. g the GUI lei 14 Basie Operation meo 14 Memory contig rat r ss a sp aena e neces lve EAA Eai ENKER EAA Ea iKi 18 Triggering ANTI 19 fietnalimggereonigialonigGa aero 20 User calibration SE ui tetet 21 DEVICE E E E E E E EE 21 Using Matlab to analyze stored data iii 23 Operation of the instrument using Matlab iii 26 Access the USBdfivericeeinre 26 VSB Seting S usas li A GE E ncie as 26 TRANSE protocol AE aiai 26 BUFSEIransieh cranio 27 Operation of the instrument using other programs 28 Firmware Upgrade 28 ACIONYM E rr 28 Novoptel 3 of 28 PM1000_UG_0_2_5_n02 doc Introduction This user guide is valid and applicable not only for PM1000 but also for PM500 The PM1000 polarimeter measures all 4 Stokes parameters at a rate of 100 MHz The samples can be averaged to increase accuracy at low optical input power Three normalization modes can be chosen The calculated states of polarization SOPs are displayed on a Poincar sphere at a connected monitor This allows the polarimeter to be used without extra computer It also enables realtime Poincar sphere display at up to 50 MHz at 100 MHz only every second sample is displayed To explore the temporal evolution of the polarization the user can switch the display to oscilloscope view In this mode the Stokes parameters are recorded in the polarimeter s memory and then plotted over time The memory size is 4 3 Gb i e 67 M pola
18. l Trigger Calibration Device Test Stokes Power Power in pw fractional bits 4 V auto ME 18 2 256 KiS Block Memory Recording Time 5 4 aaa Trigger Event Recording Start i ii Recording Multiple Events 256 Events Auto Reactivate Events 000 Auto Save 10 Times Fil HDD 4 Sub Dirs Show Sphere Memory Show Scope Memory Memory exponent The block size of the memory is defined by a memory exponent between 10 and 26 see section Fundamental PM1000 configuration The memory recording time derived from block size and averaging time is displayed accordingly Power or DOP recording The memory stores 4 Stokes parameters at once For the parameter So the GUI allows to select either optical power or degree of polarization DOP for recording If power is selected the unit of So will be uW To increase accuracy the 16 bit integer value can be shifted bitwise to add some fractional bits before recording If the option auto is selected the number of fractional bits will be selected automatically according to the current input power level Data file types The data can be saved in binary or text file format The binary format uses less disk space and works faster whereas the text format allows an easier processing of data with external programs The data type can be chosen in the menu strip Tools gt Select Data File Type Both file types start with an ASCII text header for additional data e g
19. ld can be adjusted between 0 always trigger and 1 never trigger in steps of 0 01 Delayed measured SOP for reference The reference Stokes vector can be a copy of the permanently measured SOP that has been delayed by a specified time The delay time is specified by the number of clock cycles tau and an exponent for clock division clkexp Based on an initial clock period of 10 ns the delay Ty can be calculated by Ty 10 ns tau 2 P By the angle and the time Tg a certain SOP changing speed T is specified The PM1000 will be triggered whenever the optical input signal surpasses this speed Please note that for correct operation the delay time should always be longer than the averaging time set by ATE Novoptel 20 of 28 PM1000_UG_0_2 5 n02 doc External user specified SOP for reference It is possible to define an arbitrary Stokes vector as reference To do so enter three Stokes parameters separated by semicolons in the text field of the drop down box and press Set The Stokes vector will be normalized and transmitted to the polarimeter One can also select one of the predefined Stokes vectors from the drop down list Or set the current measured SOP as reference by pressing the button Set Cur SOP User calibration set By default the internal factory calibration set is used Using the GUI a user calibration set can be loaded to and from the polarimeter It can also be stored in the polarimeter s permanent memory Fl
20. lit char transpose C char 13 try eval char headerstrings 1 Novoptel 24 of 28 PM1000_UG_0_2 5 n02 doc catch err disp sprintf ERROR Unknown command s char headerstrings 1 pause end get the full header with meta data fseek FID 0 bof C fread FID headerlength uint8 headerstrings strsplit char transpose C char 13 size headerstrings size headerstrings nlines size headerstrings 2 load information from meta data if nlines gt 2 for ii 2 nlines l try eval char headerstrings ii catch err disp sprintf ERROR Unknown command s char headerstrings ii pause end end end get the data after the header fseek FID headerlength bof C fread FID uint16 get the stokes parameters N reshape C 4 floor length C 4 remove offset from stokes parameters 1 3 N 2 4 N 2 4 2415 close the data file fclose FID plot the data x l length N 1 SamplePeriod_ns 10 9 X Axis in seconds x l length N 1 X Axis in samples plot Ni 2815 esto x N amp i 2 15 Tacr e x NO ZA O ib 2e N31 Ig legend DatalName Stokes 1 Stokes 2 Stokes 3 xlabel Seconds Novoptel 25 of 28 PM1000_UG_0_2_5_n02 doc Operation of the instrument using Matlab The USB driver has to be installed on your system and the instrument needs to be connected using a USB cable Examples of Matlab communication scripts can be downloaded
21. malized 15 fractional bits Offset 2 512 42 LS2Nn 15 0 R Latched copy of S2Nn updated on any read of EPow 512 43 LS2Nn 15 0 R Latched copy of S2Nn updated on any read of EPow 512 44 LS3Nn 15 0 R Latched copy of S3Nn updated on any read of EPow 512 46 SINrm 1 0 R W Stokes parameters vector normalization mode see section Fundamental PM1000 configuration 00 Non normalized 01 Standard normalization 10 Exact normalization 512 48 UCal 15 0 RW User calibration matrix M with elements MOO MO1 si M02 M03 M10 M11 M12 M13 M20 M21 M22 512 63 M23 M30 M31 M32 M33 Non normalized Stokes vector M photocurrent vector 512 64 UCalSL 3 0 RAW Floating point position of user calibration matrix 512 65 SelUCal 0 R W 1 switches to user defined calibration matrix 1 WwW 1 writes user calibration matrix to flash RAM 512 67 MinFreq 15 0 R Minimum extrapolated optical frequency in GHz 10 16 bit unsigned 512 68 MaxFreq 15 0 R Maximum extrapolated optical frequency in GHz 10 16 bit unsigned 512 69 CurFreq O R W Current optical frequency in GHz 10 16 bit unsigned 512 70 MinCalFr 15 0 R Minimum calibrated optical frequency in GHz 10 16 bit unsigned 512 71 MaxCalFr 15 0 R Maximum calibrated optical frequency in GHz 10 16 bit unsigned 512 72 0 W SDRAM write trigger Any write of 1 to this register Novoptel 7 of 28 PM1000_UG_0_2_5_n02 doc bit
22. on time of 2 1E 10 ns is achieved ATE ranges from O 100 MS s to 20 95 4 S s Normalization mode The PM1000 provides three choices for the normalization of Stokes parameters vectors e Standard normalization Stokes vectors are normalized to unit length Regardless of power and DOP they appear at the surface of the Poincar sphere e Exact normalization Stokes vectors are normalized only with respect to optical power For DOP lt 1 or DOP 0 they appear inside or in the center of the Poincar sphere e Non normalized Stokes vectors are normalized only with respect to a user defined power value 1 mW by default This means that DOP and optical power determine the length of the displayed Stokes vector up to a maximum length of 1 Memory exponent ME The memory exponent ME defines the size of the internal memory block that is being written into The smallest block is achieved with ME 10 2 1024 samples The largest block is achieved with ME 26 27 67 108 864 samples The memory recording time is derived from ME ATE and the sampling time 10 ns At highest speed ATE 0 the memory is filled within 0 67 seconds since 27 2 10 ns 0 67 s Register description Basic functions of the PM1000 are configured using the front control buttons Advanced functions can be controlled through the USB or SPI port by reading and writing to internal registers which are described in the following table Note that the register
23. one SOP event has been recorded the different events can be selected for plotting by up and down buttons EventNr 1 Pa The GUI oscilloscope plot allows to derive the SOP changing speed from the stored SOP samples Black curve Elsa Power DOP ata After selecting Speed from the drop down list the black curve in the plot will show the SOP speed instead of Power or DOP The SOP speed plot is normalized to its maximum which is displayed at the upper right of the plot Since the SOP speed is calculated sample to sample it will contain a lot of noise when observing slow SOP changes with small ATE N Novoptel PM500 PM1000 Scope oe s 1 Stokes 1 Stokes2 Stokes3 Blackcuve Speed v EventNii 1 5 Speed 48 43 kradis y 1 0 Grid 200 usiDiv gt Save data screen span Full sampling depth For deeper SOP analysis with other programs like Matlab the data displayed in the oscilloscope plot can be stored into a file on the computer by pressing Save data screen span If the checkbox Full sampling depth is activated the memory will not be undersampled again and every stored sample will be copied to the computer Novoptel 17 of 28 PM1000_UG_0_2 5 n02 doc Memory configuration The PM1000 internal memory allows to store up to 67 M SOP samples at a rate of up to 100 MS s It is configured in the Memory tab of the main tab control Memory Triggering Gating Interna
24. ording process will be paused as long as the gating signal is active Novoptel 19 of 28 PM1000_UG_0_2 5 n02 doc Memory Triggering Gating Internal Trigger Calibration Device Test Internal signal Disabled Rising edge active high Triggering Falling edge active low Gating External signal BNC o i os F F ci O Rising edge active high Mi Falling edge 4 active low Gating The internal triggering gating signal is the result of an internal Stokes vector multiplication see next section The external triggering gating signal is a LVCMOS33 0 V 3 3 V signal that is applied to the BNC connector at the rear panel of the instrument Internal trigger configuration The internal trigger signal can be configured in the nternal Triggertab of the GUI This signal is the length of a difference vector between the current and a reference Stokes vector normalized to a maximum of 1 It is therefore a function of the angle between the two Stokes vectors Trigger threshold 0 5 Scur Sret sin 3 2 For small it holds trigger threshold 6 2 Memory Triggering Gating Internal Trigger Calibration Device Test Current Trigger Signal 03 0 Trigger Threshold 010 amp 0 20 rad E gt E Reference Vector Delayed Measured SOP tau 31 clkexp 6 S 19840ns Corresp SOP variation 10 10 krad s External SOP Reference 1 00 0 00 0 00 Set SetCur SOP The trigger thresho
25. p2 50 ATEZ 195 Ust 0000 U62 0000 U7I 0000 U72 0000 Status Idle Cancel Close Starting at 0 all 16 electrode voltages are modified subsequently Step size and averaging time can be selected separately for the first and last 8 voltages After measuring the optical power at maximum and minimum transmission the calculated PDL will displayed PDL Evaluation xa Extinction Method Max Power 1091 24 pv Min Power 567 11 pi PDL 2 8425 dB PDL by Mueller matrix PDL can also calculated from the Mueller matrix of a DUT To measure the Mueller matrix of a DUT first a number of voltage sets that lead to predefined polarization states have to be found Examples for such polarization states are the corners of diamonds cubes and other polyhedrons The GUI allows to choose between 6 8 and 14 polarization states where 6 corresponds to the 6 normal vectors on the surface of a cube 8 corresponds to the 8 corners of this cube and 14 is a combination of the two With a patch cord connected between scrambler transformer and polarimeter instead of the DUT the GUI searches for the corresponding number of voltage sets after you have clicked on Run Ref Meas After the DUT has been connected again the DUT Measurement can be started In order to get appropriate results the input polarization to the scrambler transformer must not change between Reference and DUT measurement After the
26. pling exponent for SDRAM readout 4 bit unsigned 512 96 0 R Read 1 if SDRAM to BlockRAM copy is in progress W SDRAM to BlockRAM copy trigger 512 97 15 0 RW Bits 15 0 of SDRAM to BlockRAM read address 512 98 9 0 RW Bits 25 16 of SDRAM to BlockRAM read address 512 99 15 0 R SDRAM output word 1 unsigned 16 bit 512 100 15 0 R SDRAM output word 2 15 fractional bits Offset 2 512 101 15 0 R SDRAM output word 3 15 fractional bits Offset 2 512 102 15 0 R SDRAM output word 4 15 fractional bits Offset 2 512 104 15 0 W Code 39293 triggers SDRAM high speed transfer 512 105 15 0 RW Bits 15 0 of SDRAM high speed read address 512 106 9 0 R W Bits 25 16 of SDRAM high speed read address 512 107 15 0 R W Number of addresses to be transferred in SDRAM high speed mode 512 128 15 0 R Firmware version as 4 digit BCD 512 129 15 0 R Device DNA word 3 DNA bits 63 48 same as read via JTAG 512 130 15 0 R Device DNA word 2 DNA bits 47 32 same as read via JTAG 512 131 15 0 R Device DNA word 1 DNA bits 31 16 same as read via JTAG 512 132 15 0 R Device DNA word 0 DNA bits 15 0 same as read via JTAG 512 133 15 0 R Module Serial Number 512 134 15 0 R Maximum input power in uW 512 144 15 0 R Module Type as 32 character string Beginning at Lu 512 144 each Register contains two bytes 512 159 representing two ASCll coded characters 512 186 1 0 R W Selects display type at connected monitor
27. put signal and press the RIGHT button twice The new dark current values are then stored in the correspondent registers Sphere oscilloscope This menu item lets you select between the following display modes Poincar live The current SOP is displayed as a point in or on the Poincar sphere The SOPs are plotted in red if they lie on the front side of the sphere and blue if they lie on the back side Points of past SOPs are kept in infinite persistence According to the selected ATE averaging value new points are plotted with a frequency of up to 50 MHz Pushing the center button or rotating the sphere clears the SOPs on the sphere Poincar memory SOPs stored in the memory are being displayed This is useful if you want to explore the evolution of a recorded SOP event in the Stokes space If the sphere is rotated memory data is loaded anew Oscilloscope The 4 Stokes parameters stored in the memory are being plotted as curves over time to illustrate the temporal evolution of a recorded SOP event Push the center button to trigger a new measurement Factory User calibration By default the PM1000 uses an internal factory calibration set which is valid for the specified wavelength range By the GUI the user can also write read user calibration data to from the polarimeter which is valid for only one specific wavelength The user calibration can be Novoptel 10 of 28 PM1000 UG 0 2 5 n02 doc stored permanently in the polarim
28. r in uW integer part 512 11 SOuWL 15 0 R Input power in uW fractional part Updated at last read of SOUWU 512412 StuWU 15 0 R S1 of Stokes vector normalized to 1 uW integer part Offset 2 512413 StuWL 15 0 R S1 of Stokes vector normalized to 1 uW fractional part Updated at last read of StuWU 512 14 S2uWU 15 0 R S2 of Stokes vector normalized to 1 uW integer part Offset 2 512 15 S2uWL 15 0 R S2 of Stokes vector normalized to 1 uW fractional part Updated at last read of S2uWU 512 16 S3uWU 15 0 R S3 of Stokes vector normalized to 1 uW integer part Offset 2 512 17 S3uWL 15 0 R S3 of Stokes vector normalized to 1 uW fractional part Updated at last read of S3uWU 512 18 LS1uWU 15 0 R Latched copy of S1uWU updated on any read of SOuWU 512 19 LStuWL 15 0 R Latched copy of StuWL updated on any read of SOuWU 512 20 LS2uWU 15 0 R Latched copy of S2uWU updated on any read of SOuWU 512 21 LS2uWL 15 0 R Latched copy of S2uWL updated on any read of SOuWU 512 22 LS3uWU 15 0 R Latched copy of S3uWU updated on any read of SOuWU 512 23 LS3uWL 15 0 R Latched copy of S3uWL updated on any read of SOuWU 512 24 DOPSt 15 0 R Degree of polarization DOP 16 bit unsigned 15 fractional bits 512425 Sist 15 0 R S1 of Stokes vector Standard Normalization 15 fractional bits Offset 2 512426 s2st 15 0 R S2 of Stokes v
29. rization states can be recorded The user can shift the oscilloscope plot and zoom into via the front control buttons The recording process can be triggered either externally by a BNC input signal or internally by defined SOP events Pre and post trigger data is stored The memory can be read out via the SPI or USB interface To configure the polarimeter a graphical user interface GUI can be started on a PC that is connected to the polarimeter by USB The GUI can also load screenshots of the connected monitor to the PC and display the Poincar sphere Rear panel Figure 1 shows the rear panel of the PM1000 BNC AIR IN E IR OU Q Tuo Am HDMI SPI JTAG USB POWER SWITCH GI 5V IN A Gs Fig 1 PM1000 rear panel External monitor A monitor can be connected to the HDMI output The HDMI port outputs 1440 x 900 pixels at 60 Hz A HDMI to DVI cable is included It must be ensured that the connected monitor supports this input mode Novoptel 4 of 28 PM1000_UG_0_2 5 n02 doc Fundamental PM1000 configuration Optical frequency The optical frequency value can be adjusted to match that of the analyzed optical input signal Averaging time ATE For accurate SOP measurement at lower optical input powers internal averaging after the 100 MS s AD conversion is recommended The averaging time is denoted by the averaging time exponent ATE 2 samples are averaged and an effective conversi
30. sampling and averaging time Sample scripts for opening and plotting data in Matlab can be provided by Novoptel They are described in the end of this document Trigger event recording A measurement is started by pressing the button Activate In normal recording mode the measurement stops when the memory block is filled completely or when the button is pressed again The checkbox Trigger Event Recording enables the continuous cyclic recording mode In this mode the measurement process is repeated without interruption until a trigger event occurs This trigger event can be launched from an internal or external signal see next section After a trigger event half of the block size is still recorded In the block data loaded Novoptel 18 of 28 PM1000_UG_0_2 5 n02 doc from the memory starting at the stop address the trigger event will be in the middle N Novoptel PM500 PM1000 Scope bo ea Stokes 1 Stokes 2 Stokes3 Black curve Power DOP v Event Nr 5 l Power 1 149 mW p 1 0 Grid 50 usiDiv fey aj e gt Save data screen span Full sampling depth To stop the recording immediately the button Activate can be pressed a second time If the checkbox Multiple Events is activated the recording will continue in the next memory block after the post trigger data of the first event has been recorded The number of events to be recorded can be selected The maximum number of ev
31. ta word is sent first LSB last If a valid register read RDREG command is received the SDO output register shifts with falling edge of SCK to transmit the requested data word Otherwise SDO remains in high impedance state Data transfer to the device continues directly after transmitting a register write NRREG command Serial interface SPI commands Command Code Data Function RDREG OXXXh OUT Read register XXXh for definition see USB section WRREG 1XXXh IN Write register XXXh for definition see USB section Serial interface SPI timing ce ee ae bai Bi Tescx gt da Tspcxi SDCK A A dae td tH e ing Tspcxa so 5 ds dm gt hi Tse UP gt Tio so T____ HU gt Taro Fig 2 Timing of SPI port Symbol Description Min Max Units Tosck CS low to SDCK high 120 ns Tekes SDCK low to CS high 120 ns TsockL SDCKL low time 1 us Novoptel 12 of 28 PM1000_UG_0_2_5_n02 doc TspckH SDCKL high time 1 us Tsetup SDI egde to SDCK high setup time 30 ns THoLp SDCK to SDI edge hold time 30 ns Tcko SDCK edge to stable SDO 100 ns Novoptel 13 of 28 PM1000_UG_0_2 5 n02 doc Operation of the instrument via graphical user interface Installing the GUI Any previous version of the graphical user interface has to be uninstalled first For installation execute setup exe in the folder PM_GUI_XXXX Follow
32. ter every window resize or sphere rotation the memory will be loaded again The loading progress is displayed in the lower right corner Oscilloscope plot The stored Stokes parameters can also be displayed in an oscilloscope plot over time by pressing Show Oscilloscope Show Oscilloscope Four traces are being plotted in the new window The three Stokes parameters S S3 plus either power or DOP whichever has been selected for memory recording see section Memory configuration In the plot the DOP will be normalized to 2 which means that a DOP of 1 will appear in the middle of the y range The power curve will be normalized to the maximum value in the data set The value is displayed in mW in the top right corner of the plot Novoptel 16 of 28 PM1000_UG_0_2 5 n02 doc N Novoptel PM500 PM1000 Scope o ea 4 Stokes 1 Stokes2 Stokes3 Black curve Powe DOP EventNr 1 _Power 1 154 mW f Ip j i il 0 i i PAVE AWIN i y A 0 Grid 200 psiDiv a a gt Save data screen span Full sampling depth The plot can be zoomed in out and shifted right and left To restrict loading time only 2048 samples are being displayed If the memory contains more data it is undersampled accordingly For a full oscilloscope plot of large memory areas up to 67 M SOPs the oscilloscope plot displayed on the monitor connected to the PM1000 can be used When more than
33. variable Timestamp is a timestamp at the beginning of data transfer With a time offset between 0 and 100 ms this refers to the moment of the last recorded sample In cyclic triggered recording mode this timestamp can be used to estimate the triggering moment with an uncertainty of about 100 ms when the duration of post trigger data sampling is subtracted ATE ME and Normalization refer to the selected settings of the same name SamplePeriod_ns is the sample period in nanoseconds derived from ATE and any undersampling When the PM1000 is in cyclic triggered recording mode CyclicRecording 1 TriggerConfiguration refers to the trigger signal configuration register 512 86 and TriggerThreshold is the value of the trigger threshold register 512 91 Data Name is either Power or DOP depending on the data selection for SO When Power is selected the value PowerLeftShift determines the amount of fractional bits in the data of SO Novoptel 23 of 28 PM1000_UG_0_2 5 n02 doc In contrast to binary files the byte length of the header in text files is not specified Hence the variable headerlength is missing Instead all lines of the header begin with a hash sign to distinguish header from subsequent measurement data Read data from text files The measurement data in text files are comma separated values that also allow opening the file in Excel for instance The following Matlab function will open a text file and plot the cont
34. will trigger a recording of the sampled SOPs in the SDRAM Recording period is defined by averaging ATE register 512 1 2 samples will be recorded defined by the memory exponent ME register 512 73 R SDRAM busy 1 if recording is in progress 1 R 1 if post trigger data recording is in progress 2 R W Continuous cyclic memory recording enabled 1 or disabled 0 3 R 1 if a full memory block was recorded since the last trigger W 1 enables automatic retrigger for next memory block 4 R 1 if SDRAM is busy due to oscilloscope display 5 R 1 if SDRAM is busy due to Poincar sphere display 512 73 4 0 RAW SDRAM memory exponent ME max 26 512 74 3 0 R W Negative exponent for 16 bit power vector recorded to SDRAM The recorded data represents power in uW left shifted bitwise by this value The shifting reduces quantization errors when recording at low input powers 512 75 0 RAW 0 selects Power Stokes to be recorded 1 selects DOP Stokes 1 R Power DOP selection updated at last SDRAM trigger 512 76 15 0 R Current write address of SDRAM bits 15 0 512 77 9 0 R Current write address of SDRAM bits 25 16 512 78 15 0 R The number of recorded Blocks after last SDRAM trigger 512 79 15 0 R W Selects a memory block 512 80 15 0 R The stop address in the selected memory block bits 15 0 512 81 9 0 R Th
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