70013301 CSM-39400M Cover.ai
Contents
1. Users Guide 4000 mA Current Source Module CSM 39400M DH LX LS Newport Corporation Brand ILX Lightwave Corporation 31950 Frontage Road Bozeman MT U S A 59715 U S amp Canada 1 800 459 9459 International Inquiries 406 556 2481 Fax 406 586 9405 ilx custhelp com www ilxlightwave com 70013301 June 2001 SAFETY AND WARRANTY INFORMATION The Safety and Warranty Information section provides details about cautionary symbols used in the manual safety markings used on the instrument and information about the Warranty including Customer Service contact information Safety Information and the Manual Throughout this manual you will see the words Caution and Warning indicating potentially dangerous or hazardous situations which if not avoided could result in death serious or minor injury or damage to the product Specifically A CAUTION Caution indicates a potentially hazardous situation which can result in minor or moderate injury or damage to the product or equipment A warnine Warning indicates a potentially dangerous situation which can result in serious injury or death Ak Zn WARNING Visible and or invisible laser radiation Avoid direct exposure to the beam General Safety Considerations If any of the following conditions exist or are even suspected do not use the instrument until safe operation can be verified by trained service personnel e Visible damage e Severe transport stres2. 0 Operation This section describes the procedures for connecting and running a laser diode with the CSM 39400M module Refer to Chapter 2 for front panel description and operation Refer to Figure 4 1 for the following discussion of connections to the CSM 39400M Module Locking Screw Modulation Connector Monitor Photodiode Bias Adjust Auxiliary Monitor Photodiode Feedback Connector Laser Diode Connector Module Locking Screw Figure 4 1 CSM 39400M Back Panel 39400M 4 4 1 The LASER Connector On the back panel of the CSM 39400M you will find a 9 pin D connector for the LD connections The pinout diagram for this connector is shown in Figure 4 2 Laser Cathode PD Anode PD Cathode Chassis Ground Interlock LED Anode LED Cathode 11 12 13 Laser Anode 14 Fan 12 VDC 15 Fan Return Figure 4 2 Back Panel LD Connector 4 2 Connecting to Your Laser When connecting laser diodes and other sensitive devices to the CSM 39400M we recommend that the LDC 3900 be powered up and the LASER output be off LASER MODE ON LED unlit In this condition a low impedance shunt is active across the output terminals When disconnecting devices it is only necessary to turn the LASER Output off 4 3 Laser Diode Connections and Shielding IMPORTANT Before connecting the laser diode to the LDC 3900 Modular Laser Diode Controller be sure that the front panel LASER MODE ON switch is in the OFF position ON LED unli
3. 4 2 and 5 4 4 to calibrate the CSM 39400M remotely 5 4 1 Local Operation Current Source Calibration The following procedure is for local front panel operation See Section 5 4 2 for remote calibration of the current source a Select the CSM 39400M to be calibrated by pressing the appropriate ADJUST switch Set the LASER current limit LIM J to full scale bandwidth as desired and current set point to 3200 mA 80 of full scale Measure the exact resistance of the 1 50 W resistor and record it Calculate the current in the following steps by using Ohm s Law I E R where E is the accurately measured voltage across the resistor and R is the accurately measured load resistance A 4 point probe resistance measurement is recommended Connect the 1 Q 50 W resistor and a calibrated DMM in parallel to measure the voltage across the output pins 5 and 8 b Turn the LASER ENABLE ON switch and press the appropriate OUTPUT switch to turn the LASER output on If the LASER output is not on the LASER I calibration mode cannot be entered c Enter the LASER I calibration mode by pushing the GPIB LOCAL and LASER DISPLAY I switches at the same time The LASER display will indicate output current in mA The LDC 3900 will beep when it is ready to accept a new calibration value d Press and hold in the PARAMETER SET switch and turn the ADJUST knob until the LASER display indicates the same current as calculated from the voltage
4. ADJUST switch With the LASER output off connect a calibrated ammeter to the PD Anode output of the CSM 39400M and connect the circuit of Figure 5 1 to the LASER and PD outputs If a calibrated ammeter with 0 1 LA resolution is not available place a calibrated DMM with 0 1 mV resolution to measure the voltage across the resistor R1 as shown in Figure 6 1 Calculate the current in the following steps by using Ohm s Law I E R where E is the accurately measured voltage across the resistor and R is the accurately measured load resistance A 4 point probe resistance measurement is recommended b Set the LASER current limit LIM I to 4000 mA Set eko set point to 16 000 uA and set the CAL PD parameter to zero This puts the CSM 39400M into a constant Ipp mode c Turn the LASER ENABLE ON switch and press the appropriate OUTPUT switch to turn the LASER output on If the LASER output is not on the LASER I calibration mode cannot be entered d Press the GPIB LOCAL and LASER DISPLAY Ipp Ppp switches at the same time to place the CSM 39400M in its LASER Ipp Calibration mode After a few seconds the LDC 3900 will beep and the LASER display will show the Ipp set point value 39400M 14 Interlock 1 Interlock 2 LD Cathode 5 LD Anode 9 PD Cathode 6 gt PD Anode 7 9 Pin D Sub 9 V Batt lpd Current CALIBRATION CIRCUIT Figure 5 1 Ipp Calibration Circuit e After the value on the L
5. damage when returning the instrument to ILX Lightwave ILX recommends you insure the shipment If the original shipping container is not available place your instrument in a container with at least 3 inches 7 5cm of compressible packaging material on all sides We look forward to serving you even better in the future Safety and Warranty Information tt Lightwave CSM 39400M 4000 mA Current Source Module Instruction Manual 1 0 Introduction The CSM 39400M 4000 mA Current Source is a precision current source module for use in the LDC 3900 Modular Laser Diode Controller It is specifically designed for use with MOPA and or Tunable Lasers It may be installed in any of the four bays on the rear of the LDC 3900 and may readily be interchanged with any other LDC 3900 module Features of the CSM 39400M include 20 W power output 4 A 5 v Service free modularity calibration information is stored on the CSM 39400M Closed case calibration High stability low noise design Flexible setup with LDC 3900 Save Recall front panel functions Photodiode feedback control mode Modulation input LED and Fan drives accommodate MOPA and Tunable lasers 2 0 CSM 39400M Specifications Current Source Set Point Accuracy 8 mA Set Point Resolution 60 HA Compliance Voltage fixed 5 V maximum Temperature Coefficient lt 100 ppm C Stability2 for 1 hour lt 10 ppm Stability for 24 hours lt 50 ppm Noise and Ripple High Bandwid
6. days whichever is greater Claims for Shipping Damage When you receive the instrument inspect it immediately for any damage or shortages on the packing list If the instrument is damaged file a claim with the carrier The factory will supply you with a quotation for estimated costs of repair You must negotiate and settle with the carrier for the amount of damage Safety and Warranty Information Comments Suggestions and Problems To ensure that you get the most out of your ILX Lightwave product we ask that you direct any product operation or service related questions or comments to ILX Lightwave Customer Support You may contact us in whatever way is most convenient Phone assessment scale 800 459 9459 or 406 586 1244 FAX EE Drees ee NT 406 586 9405 Email peloton ru ee Ornate ee support ilxlightwave com Or mail to ILX Lightwave Corporation P O Box 6310 Bozeman Montana U S A 59771 www ilxlightwave com When you contact us please have the following information Model Number Serial Number End user Name Company Phone Fax Description or sketch of what is connected to the ILX Lightwave instrument Description of the problem If ILX Lightwave determines that a return to the factory is necessary you are issued a Return Authorization RA number Please mark this number on the outside of the shipping box You or your shipping service are responsible for any shipping
7. measurement as described in step a e Release the PARAMETER SET switch to accept the first calibration value After the LASER DISPLAY SET switch is released the LDC 3900 will beep It will then apply the second calibration current approximately one fourth of the original current 39400M 12 f The LDC 3900 will beep when it is ready to accept the second calibration value When it does press and hold in the PARAMETER SET switch and turn the ADJUST knob until the LASER display indicates the same current as calculated from the voltage measurement as described in step a g Release the PARAMETER SET switch to accept the second calibration value After the PARAMETER SET switch is released the LDC 3900 will calculate the calibration constants store them to nonvolatile memory on the CSM 39400M beep and return to its former before calibration state h Repeat this procedure with the other bandwidth if desired 5 4 2 Remote Operation Current Source Calibration The following procedure is for remote GPIB operation See Section 5 4 1 for local calibration of the current source a Select the CSM 39400M to be calibrated by sending the LAS CHAN x command where x is the channel of the CSM 39400M Set the LASER limit to full scale via the LAS LIM I 4000 command output bandwidth as desired via the LAS MODE command and current set point to 80 of full scale via the LAS LDI 3200 command Connect a calibrated DMM to measure
8. the voltage across the laser output pins 5 and 8 Calculate the current in the following steps by using Ohm s Law I E R where E is the accurately measured voltage across the resistor and R is the accurately measured load resistance A 4 point probe resistance measurement is recommended b Turn the LASER ENABLE ON switch Enter the LAS OUT ON command to turn the LASER output on If the LASER output is not on the LASER I calibration mode cannot be entered c Enter the LASER I calibration mode by issuing the LAS CAL LDI command The LDC 3900 will beep when it is ready to accept the first calibration point d Input the first actual as calculated in Step a LASER output current as an lt nrf value gt via the LAS LDI lt nrf value gt command If this value is to be measured and entered remotely via a GPIB controlled DMM for example the measured value of the current should not be entered until the LDC 3900 is ready to receive it The LDC 3900 will be ready to receive the current value when after a LAS CAL LDI query is sent the response from the LDC 3900 is 1 e Once the actual I value is entered via the LAS LDI command the LDC 3900 will beep and will apply a new current equal to approximately one fourth 1 4 the previous set current The LDC 3900 will be ready to receive the second current value when after a LAS CAL LDI query is sent the response from the LDC 3900 is 1 f Input the second actual
9. 00 LA mW 0 01 uA mW 0 5000 0 mW 0 1 mW 5 digit green LED 0 4000 mA 20 mA 40 mA 15 pin high density D sub Coax BNC Coax BNC instrumentation amplifier input SMaximum output current transient resulting from normal operational situations e g power on off as well as accidental situations e g power line plug removal For more information refer to ILX Noise and Transient Test Standards publication 6Maximum output current transient resulting from a 200V power line transient spike For more information refer to ILX Noise and Transient Test Standards publication 7Maximum monitor photodiode current drift over any 30 minute period Constant power mode stability specification assumes zero drift in detector responsivity 39400M 2 3 0 Installation This section describes the procedures for installing and removing a CSM 39400M module from the LDC 3900 NOTE The LDC 3900 will power up in a default state upon detecting any change in the LDC 3900 system configuration such as installing a new module All parameters and SAVE RECALL settings will be set to default values based on the new configuration Calibration data is stored in the CSM 39400M module itself and is never lost due to reconfiguration of the LDC 3900 To install the CSM 39400M module into the LDC 3900 follow these steps 1 Turn the power off on the LDC 3900 2 Place the CSM 39400M module into an open bay on the back of the LDC 3900 and slide t
10. ASER display is stable has not changed by more than one digit for several seconds the CSM 39400M is ready for the actual Ipp value to be entered Press and hold in the PARAMETER SET switch and turn the ADJUST knob until the LASER display shows the correct value as shown on the calibrated ammeter or the calculated I value from Step a f Release the PARAMETER SET switch to store the first calibration value into non volatile memory It will then expect the second calibration current approximately one fourth of the original current g The LDC 3900 will beep when it is ready to accept the second calibration value When it does press and hold in the PARAMETER SET switch and turn the ADJUST knob until the LASER display indicates the same Ipp current as measured directly or as calculated in Step a from the measured voltage h Release the PARAMETER SET switch to accept the second calibration point After the PARAMETER SET switch is released the LDC 3900 will calculate the calibration constants store them to nonvolatile memory on the CSM 39400M beep and return to its former before calibration state 5 4 4 Remote Operation Ipp Current Calibration The following procedure is for calibrating the LASER constant current source over GPIB This procedure calibrates the feedback circuits for constant lpp and constant Ppp modes When these values are reached and are stable the user enters the actual value of the current as measured
11. al or consequential damages If a problem occurs please contact ILX Lightwave Corporation with the instrument s serial number and thoroughly describe the nature of the problem Returning an Instrument If an instrument is to be shipped to ILX Lightwave for repair or service be sure to 1 Obtain a Return Authorization number RA from ILX Customer Service 2 Attach a tag to the instrument identifying the owner and indicating the required service or repair Include the instrument serial number from the rear panel of the instrument 3 Attach the anti static protective caps that were shipped with the instrument and place the instrument in a protective anti static bag 4 Place the instrument in the original packing container with at least 3 inches 7 5 cm of compressible packaging material Shipping damage is not covered by this warranty 5 Secure the packing box with fiber reinforced strapping tape or metal bands 6 Send the instrument transportation pre paid to ILX Lightwave Clearly write the return authorization number on the outside of the box and on the shipping paperwork ILX Lightwave recommends you insure the shipment If the original shipping container is not available place your instrument in a container with at least 3 inches 7 5 cm of compressible packaging material on all sides Repairs are made and the instrument returned transportation pre paid Repairs are warranted for the remainder of the original warranty or for 90
12. by an external DMM The CSM 39400M then automatically calibrates the LASER feedback circuits This procedure is for remote GPIB operation See Section 5 4 3 for local calibration of the Ipp current a With the LASER output off connect a calibrated ammeter to the PD Anode output of the CSM 39400M and connect the circuit of Figure 5 1 to the LASER and PD outputs 39400M 15 If a calibrated ammeter with 0 1 LA resolution is not available place a calibrated DMM with 0 1 mV resolution to measure the voltage across the resistor R1 as shown in Figure 5 1 Calculate the current in the following steps by using Ohm s Law I E R where E is the accurately measured voltage across the resistor and R is the accurately measured load resistance A 4 point probe resistance measurement is recommended Select the CSM 39400M to be calibrated by sending the LAS CHAN x command where x is the channel of the CSM 39400M Set the LASER current limit via the LAS LIM I 4000 command Set the Lo set point to 16 000 uA via the LAS MDI 16000 command Set the CAL PD parameter to zero via the LAS CALMD 0 command This puts the CSM 39400M into a constant Ipp MDD mode Turn the LASER ENABLE ON switch Enter the LAS OUT ON command to turn the LASER output on If the LASER output is not on the LASER I calibration mode cannot be entered Enter the LAS CAL MDI command to place the CSM 39400M in its LASER Current Calibration mode After a fe
13. d and bit 5 of the Service Request Enable register via the SRE command Service request SRQ handling depends on your GPIB hardware Refer to your GPIB user s manual for details 39400M 16 5 4 5 Local Operation Laser Voltage Measurement Calibration The following procedure is for calibrating the LASER voltage measurement via the front panel See Section 5 4 5 for remote GPIB calibration of the voltage measurement a With the LASER output off connect a calibrated voltmeter in parallel with a 35 Q 5 Watt low temperature coefficient resistor to the LASER output of the CSM 39400M pins 5 and 8 b Select the CSM 39400M to be calibrated by pressing the appropriate ADJUST switch Set the LASER current limit LIM I to 200 mA Set the LASER Iset point to 120 mA c Turn the LASER ENABLE ON switch and press the appropriate OUTPUT switch to turn the LASER output on If the LASER output is not on the LASER voltage calibration mode cannot be entered d Press the GPIB LOCAL and LASER DISPLAY V switches at the same time to place the CSM 39400M in its LASER Voltage Calibration mode e After a few seconds the LDC 3900 will beep when it is ready to accept a new calibration value Press and hold in the PARAMETER SET switch and turn the ADJUST knob to enter the LASER voltage measurement value which appears on the DMM Release the PARAMETER SET switch to enter the value Once the actual voltage value is entered the LDC 3900 will b
14. eep It will then expect the second calibration voltage point approximately one fourth of the original voltage f Input the second actual measured LASER voltage as an lt nrf value gt as in Step e g Once the second actual voltage value is entered the LDC 3900 will beep and the new calibration constants will be calculated and stored into non volatile memory on the CSM 39400M 5 4 6 Remote Operation Laser Voltage Measurement Calibration The following procedure is for calibrating the LASER voltage measurement via GPIB See Section 5 4 5 for local calibration of the voltage measurement a With the LASER output off connect a calibrated voltmeter in parallel with a 35 Q 5 Watt low temperature coefficient resistor to the LASER output of the CSM 39400M pins 5 and 8 b Select the CSM 39400M to be calibrated by sending the appropriate LAS CHAN x command where x is the channel number of the CSM 39400M Set the LASER current limit via the LAS LIM I 200 Set the Iset point via the LAS LDI 120 command c Turn the LASER ENABLE ON switch Enter the LAS OUT ON command to turn the LASER output on If the LASER output is not on the LASER voltage calibration mode cannot be entered d Enter the LAS CAL LDV command to place the CSM 39400M in its LASER Voltage Calibration mode 39400M 17 After a few seconds the LDC 3900 will be ready for the actual laser voltage to be entered via the LAS LDV command The measured value of t
15. efore the final circuit break Therefore although the CSM 39400M provides a proprietary debounce protection circuit for the LASER output secure cabling is important It is recommended that the connections to the LDC 3900 Modular Laser Diode Controller output be made using twisted wire pairs with an earth grounded shield see Figures 4 3 A D The output terminals of the unit are left floating relative to earth ground to suppress AC power on power off transients that may occur through an earth ground path If the output circuit is earth grounded at some point such as through the laser package and mount the user must be careful to avoid multiple earth grounds in the circuit Multiple earth grounds may provide circuit paths that induce spurious currents in the photodiode feedback circuit and output leads 4 4 Photodiode Feedback Connections The connector on the back panel of the CSM 39400M contains the current supply output The photodiode signal is input at the connector at pins 6 and 7 see Figure 4 2 The CSM 39400M provides an adjustable reverse bias of 0 5 V for the photodiode To set the photodiode bias to 5 volts reverse bias turn the back panel PHOTODIODE BIAS ADJUST fully clockwise To set the photodiode bias to 0 volts reverse bias turn the back panel PHOTODIODE BIAS ADJUST fully counter clockwise The photodiode feedback may also be connected via the PHOTODIODE BNC connector located on the CSM 39400M back panel Many laser d
16. he module into place There are tracks at the top and bottom of the bay which guide the module into place Push the module into place until the board edge clicks into place with an audible pop This indicates that the module is locked into place Screw the Module Locking Screws into the back panel to secure the module It is then ready to be used in the LDC 3900 3 Power up the LDC 3900 4 After the LDC 3900 has completed its power up sequence the ADJUST LAS indicator which corresponds to the newly installed CSM 39400M module should be lit in green indicating that the module has been recognized as a LASER current source in its respective bay To remove the CSM 39400M module from the LDC 3900 follow these steps 1 Turn the power off on the LDC 3900 2 Unscrew the Module Locking Screws which secure the module to the LDC 3900 back panel 3 Grasp the CSM 39400M module by handle which extends from the bottom of the back panel Gently but firmly pull the module out of the LDC 3900 4 If the CSM 39400M module is replaced in the LDC 3900 before the LDC 3900 is powered up again the LDC 3900 will retain its memory of all parameter settings and SAVE RECALL values However if the LDC 3900 is powered up and detects a change in its system configuration all parameters and SAVE RECALL information will be lost Calibration data is stored in the CSM 39400M module itself and is never lost due to reconfiguration of the LDC 3900 39400M 3 4
17. he voltage should not be entered until the LDC 3900 is ready to receive it The LDC 3900 will be ready to receive the voltage value when after a LAS CAL LDV query is sent the response from the LDC 3900 is 1 Once the actual voltage value is entered via the LAS LDV command the LDC 3900 will beep It will then set the output to approximately one fourth of the original voltage and expect the second calibration value to be entered The LDC 3900 will be ready to receive the second voltage value when after a LAS CAL LDV query is sent the response from the LDC 3900 is 1 Input the second actual measured LASER voltage as an lt nrf value gt as in Step e Once the second actual voltage value is entered via the LAS LDV command the LDC 3900 will beep and the new calibration constants will be calculated and stored into non volatile memory on the CSM 39400M The operation complete flag bit 0 of the Standard Event Status Register may be used to trigger a service request This type of interrupt is enabled by setting bit 0 of the Service Request Enable register via the ESE command and bit 5 of the Service Request Enable register via the SRE command Service request SRQ handling depends on your GPIB hardware Refer to your GPIB user s manual for details 39400M 18
18. iode modules contain an internal photodiode that monitors the back facet emission of the laser Usually this photodiode is internally connected to either the laser anode or cathode Figures 4 2A 4 2D show the recommended connections and shielding for the various configurations of laser diode modules and photodiode feedback schemes The photodiode and laser inputs on the CSM 39400M are electrically isolated from ground and each other So if a 4 pin connection is made no common connections no additional jumpers are required Figures 4 2A 4 2D show the recommended connections and shielding for 3 pin lasers where the common connection is internal to the device A 4 pin laser should be connected with the same shielding as shown in Figure 4 2 but the common connection between the photodiode and the laser is optional 4 5 Grounding Considerations The LASER outputs of the CSM 39400M are isolated from chassis ground allowing either output terminal to be grounded at the user s option Figure 4 3 shows the proper earth ground shielding for laser diode photodiode connections 39400M 8 4 6 Modulation Connections The MODULATION connector allows a 400 mV A modulation signal to be applied to the laser The modulation port input impedance is 10 KQ 4 7 MOPA Connections The LDC 3900 may be configured for a MOPA laser i e SDL 5762 by using the CSM39400M in conjunction with a CSM39020 and a TCM39032 module The ILX SDL adaptor cable included wi
19. is suitable for continuous operation Safety Marking Symbols This section provides a description of the safety marking symbols that appear on the instrument These symbols provide information about potentially dangerous situations which can result in death injury or damage to the instrument and other components or I slash l only denotes that mains are on or 0 Caution Earth f Visible and or refer to ground TN Se invisible laser manual Terminal radiation Caution risk Protective Frame or of electric Conductor SE hot chassis shock Terminal Terminal dh On In position of a bistable push control The O LL Off Out position of a bistable push control The circle O only denotes that mains are off Safety and Warranty Information ILX Lightwave WARRANTY ILX LIGHTWAVE CORPORATION warrants this instrument to be free from defects in material and workmanship for a period of one year from date of shipment During the warranty period ILX will repair or replace the unit at our option without charge Limitations This warranty does not apply to fuses lamps defects caused by abuse modifications or to use of the product for which it was not intended This warranty is in lieu of all other warranties expressed or implied including any implied warranty of merchantability or fitness for any particular purpose ILX Lightwave Corporation shall not be liable for any incidental speci
20. measured LASER output current as an lt nrf value gt as in Step a 39400M 13 g Once the second actual I value is entered via the LAS LDI command the LDC 3900 will beep and the new calibration constants will be calculated and stored into non volatile memory on the CSM 39400M The OPC query may be used after the LAS LDI value is sent to determine when the calibration is completed The operation complete flag bit 0 of the Standard Event Status Register may be used to trigger a service request This type of interrupt is enabled by setting bit 0 of the Service Request Enable register via the ESE command and bit 5 of the Service Request Enable register via the SRE command Service request SRQ handling depends on your GPIB hardware Refer to your GPIB user s manual for details h Repeat this procedure with the other range if desired 5 4 3 Local Operation I Current Calibration The following procedure is for calibrating the LASER La constant current source This procedure calibrates the feedback circuits for constant Ipp and constant Ppp modes When these values are reached and are stable the user enters the actual value of the current as measured by an external DMM The CSM 39400M then automatically calibrates the LASER feedback circuits This procedure is for local front panel operation See Section 5 4 4 for remote calibration of the Ipp current a Select the CSM 39400M to be calibrated by pressing the appropriate
21. s e Prolonged storage under adverse conditions e Failure to perform intended measurements or functions If necessary return the instrument to ILX Lightwave or authorized local ILX Lightwave distributor for service or repair to ensure that safety features are maintained see the contact information on page vi All instruments returned to ILX Lightwave are required to have a Return Authorization Number assigned by an official representative of ILX Lightwave Corporation See Returning an Instrument on page v for more information DIS Lightwave Safety and Warranty Information SAFETY SYMBOLS This section describes the safety symbols and classifications Technical specifications including electrical ratings and weight are included within the manual See the Table of Contents to locate the specifications and other product information The following classifications are standard across all ILX Lightwave products Indoor use only Ordinary Protection This product is NOT protected against the harmful ingress of moisture Class Equipment grounded type Mains supply voltage fluctuations are not to exceed 10 of the nominal supply voltage Pollution Degree II Installation overvoltage Category Il for transient overvoltages Maximum Relative Humidity lt 80 RH non condensing Operating temperature range of 0 C to 40 C Storage and transportation temperature of 40 C to 70 C Maximum altitude 3000 m 9843 ft This equipment
22. t Before turning on the LASER output be sure that the current limit has been correctly set Figures 4 3 A D show the possible configurations of connecting laser diodes and photodiodes with the LDC 3900 Modular Laser Diode Controller 39400M 5 S CI QI OIl e Si bi A Zi ol ol oi tl Zi s gt S ai Ki el Oj D Di L Earth Ground Figure 4 3A Common Laser Cathode Photodiode Cathode a S CI Q Ol o D bi A Li ol ol oi t LI s D Si S Ol D Nj Earth Ground Figure 4 3B Common Laser Cathode Photodiode Anode 39400M 6 a gl 2 CI Q Ol e D bi A Li ol ol oi i Zi s D Si S O D Nj Earth Ground Figure 4 3C Common Laser Anode Photodiode Cathode 2 Ei C1 O1 Ol o Si bi A Zi ol ol ol 11 Zi s gt S SI S O D Di OUTPUT Earth Ground Figure 4 3D Common Laser Anode Photodiode Anode 39400M 7 IMPORTANT The cable connections to the laser must be secure enough that they won t open circuit should they be jostled or bumped Should an open circuit occur during laser operation the LASER output will be turned off QUTPUT LED unlit automatically Experience indicates that should an open circuit occur during laser operation while the LASER is ON the laser may be damaged by a momentary circuit break and remake b
23. th Mode lt 20 uA rms Low Bandwidth Mode lt 20 WA rms IAU values relate to a one hour warm up period 2Over any 1 hour period half scale output 3Over any 24 hour period half scale output 4Measured from resulting intensity fluctuations of a laser diode measured optically with a 150kHz bandwidth photodetector Measurements made with Mhz detector are typically 10 higher For more information refer to ILX Noise and Transient Test Standards publication 39400M 1 39400M Laser Current Source Specifications continued Bandwidth High Bandwidth Mode Low Bandwidth Mode Worst Case Transients Operational Power Line induced LED Drive Fan Drive Photodiode Feedback Range Output Stability Accuracy Bias Voltage Laser Drive Current Display Output Current Range Output Current Resolution Output Current Accuracy at 25 C Photodiode Current Range Photodiode Current Resolution Photodiode Current Accuracy Responsivity Range Responsivity Resolution Optical Power Range Output Power Resolution Type Current Limit Setting Range Resolution Accuracy Output Connectors Current Source Output Photodiode Input Analog Modulation Input lt 20 mA DC to 50 KHz DC to 1 KHz lt 5 mA 2V at 50 mA 12V at 130 mA 5 to 20 000 LA 4 uA 20 UA 0 5 V reverse bias 10 adjustable on back panel 0 0 to 4000 0 mA 0 1 mA 4mA 0 20 000 uA l uA 4 uA 0 600
24. th the CSM39400M should be connected as shown in Figure 4 4 below 39020 ECK Ak NY 10 5762 MOPA Figure 4 4 LDC 3900 MOPA Laser Configuration 4 8 Tunable Laser Connections The LDC 3900 may be configured for a Tunable laser i e SDL 8630 by using the CSM39400M in conjunction with a TCM39032 module The ILX SDL adaptor cable included with the CSM39400M should be connected as shown in Figure 4 5 below 39400M 9 NU HHH ea YUU yLWud Judd Ta el 1 B 1 ml ei V Ee ci SDL ADAPTOR LUDED W 39400M Figure 4 5 LDC 3900 Tunable Laser Configuration 5 0 Calibration The CSM 39400M should be calibrated every 12 months or whenever performance verification indicates that calibration is necessary All calibrations can be done with the case closed The instrument is calibrated by changing the internally stored digital calibration constants 39400M 10 5 1 Recommended Equipment Recommended test equipment for calibrating the CSM 39400M is listed in Table 5 1 Equipment other than that shown in the table may be used if the specifications meet or exceed those listed If your LDC 3900 is equipped with the model 1231 GPIB IEEE 488 2 interface you may refer to sections 5 4 2 5 4 4 and 5 4 6 for calibration procedures using the GPIB if desired RECOMMENDED TEST EQUIPMENT Description Mfg Model Specification DMM HP 3457A 0 1 uA or 0 1 mV resolution Resistor 35 Q 5 W low TCR for
25. voltage cal High power 1 Q 50 W low TCR for current cal Ten Calibration Resistors Metal Film 49 Q and 100 Q 1 1 4 W High power 5 Q 5 W low TCR Optical Isolator TIL117 or equivalent 6 pin Connector D sub 9 pin male Table 5 1 Recommended Test Equipment 5 2 Environmental Conditions Calibrate this instrument under laboratory conditions We recommend calibration at 23 C 1 0 C When necessary however the LDC 3900 Modular Laser Diode Controller may be calibrated at its intended use temperature if this is within the specified operating temperature range of 0 to 50 C 5 3 Warm Up The LDC CSM 39400M should be allowed to warm up for at least 1 hour before calibration 39400M 11 5 4 LASER Controller Calibration Procedures There are four calibration procedures that need to be followed for the CSM 39400M They are calibration of the constant current source for both bandwidths calibration of the laser voltage measurement and calibration of the constant light power Ipp feedback circuits The CSM 39400M implements a two point calibration for the Laser current source Two currents are applied to a load and the resulting measured currents are fed back by the user to the CSM 39400M The CSM 39400M calibration program uses the two data points to calculate calibration constants that it will thereafter use to set current If you have the optional Model 1231 IEEE 488 2 GPIB interface you may follow the procedure in sections 5
26. w seconds the LDC 3900 will be ready for the actual Ipp current to be entered via the LAS MDI command The measured value of the current should not be entered until the LDC 3900 is ready to receive it The LDC 3900 will beep when it is ready to accept a new calibration value The LDC 3900 will be ready to receive the ko value when after a LAS CAL MDI query is sent the response from the LDC 3900 is 1 Once the actual I value is entered via the LAS MDI command the LDC 3900 will beep and the new calibration value will be stored into non volatile memory It will then set the output to approximately one fourth of the original current and expect the second calibration value The LDC 3900 will be ready to receive the second Ipp value when after a LAS CAL MDI query is sent the response from the LDC 3900 is 1 Input the second actual measured Ipp as an lt nrf value gt as in Step d Once the second actual monitor diode current value is entered via the LAS MDI command the LDC 3900 will beep and the new calibration constants will be calculated and stored into non volatile memory in the CSM 3900 The OPC query may be used after the LAS MDI value is sent to determine when the calibration is completed The operation complete flag bit 0 of the Standard Event Status Register may be used to trigger a service request This type of interrupt is enabled by setting bit 0 of the Service Request Enable register via the ESE comman
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