Quantum Instruments Cascade Laser Starter Kit specification

Starter Kit Instruction Manual

Troubleshooting

36

Laser draws current but gives no light

-The laser may be reversed polarized (it is not a desirable situation but does gen- erally not destroy the laser).

√Check the polarity of the connection.

-The polarity is right. It draws too much current and the power meter is misaligned.

√Reduce the current at the maximum speciﬁed for the operating temperature.

√Check power meter alignement and scale.

-The QCL laser is not used with the LLH and is grounded.

√Check that there is no short-circuit on the circuit.

The laser does not draw current

-There is no contact with the laser.

√Check that the gilded copper contact is present and properly mounted.

√Tighten the PET U-shaped holder in order to eﬀective the contact with the laser by means of the POM ﬁxing screws.

√Check the connections on the LLH. Measure the input resistance with an ohm- meter between the Laser connector and the Base receptacle connector.

Image 37

Quantum Instruments Cascade Laser Starter Kit manual Laser draws current but gives no light, Laser does not draw current

Contents

Instructions Manual Web version Quantum Cascade Laser Starter Kit Contents Troubleshooting InstallationMaintenance Overview Use Appendix Document IdentiﬁcationLimited waranty Manufacturer Chapter overview GeneralGeneralities Compliance Persons GlossaryProduct Personnel Procedure style Commands styleTypographic conventions Description style Procedure eﬀects style ProblemSee page x-y Troubleshooting style Possible causePage Importance of safety instructions Safety InstructionsNon-compliance with the safety regulations Introduction Environmental conditions General safety instructionsCompliance and informa- tion System Composition Description If no conﬁguration is speciﬁed, the DN pad is used DFB and FP Quantum Cascade LasersDescription Geometry of QC lasers Speciﬁcations Electrical model Electrical model characteristics LLH100 external view description Laboratory Laser HousingLLH100 LLH100 internal view Laboratory Laser Housing internal view Thermo-Electric Cooler TEC and PT100 connections Speciﬁcations of the Peltier connector Measurement connection Speciﬁcations of the measurement connector QCL pulser switching unit front and rear view QCL pulser switching unitLDD100 Generalities QCL pulse switching measuring unitMeasured voltages Timing data Duty cycle calculation Laser peak current Average dissipation Laser peak voltageAccuracy considerations QCL pulser timing unit TPG128 Trigger and logic output signals Ω TTL driver circuit Peltier and PT100 connections QCL temperature controllerTCU151 Chapter overview Packing list InstallationGeneral Standard items Procedure Setting the appropriate AC voltage on TCU151110-120V, 60Hz USA 220-240V, 50Hz Europe Before beginning Installing the starter Kit Connecting Starter Kit QCL pulse timing unit com- mand description Use TCU151 temperature controler front panel TCU151 command description Overview Laser utilisationProceedings Starting the TPG128 Interlock utilisation Procedure Interlock utilisation Power supply reaches max cur- rent for a very low voltage TroubleshootingDC power supply is not ﬂoating Principle Laser does not draw current Laser draws current but gives no lightQCL laser is not used with the LLH and is grounded There is no contact with the laser How to remove the covers of TCU151 and TPG128 MaintenanceOverview Quantum Cascade Laser replace Ment Replacement procedures + LLH100 connection Facet on the case, it is extremely fragile Exchanging the laser QCL UP and DN position Exchange Humidity If the ambient atmosphere is humid this is Procedure interlock setting TCU151 temperature con Troller interlock settingBefore beggining interlock set Ting Needed material Procedure calibration Calibaration procedures1 TPG128 calibration Generalities TPG128 main board TPG128 main board Procedure +5V/-5V power supply check 2 TCU151 temperature controller calibration = 1.22 to Sensing level and range adjustement Temperature Reference oﬀset adjustment Setting Current/Voltage ratio adjustmentOscillator check LCD screen should display 1.00 a Starting the power section of the instru Ment 7V = 70 C If needed, adjust it with the trimmer P92 → Value displayed ≤ 1A Current adjustment→ Value displayed should tend to the deﬁned value → The temperature displayed 2 should be 035 C Miscellaneous functions testing Temperature Limit testingThreshold on → The red LED 1 should turn oﬀ Detection techniques Application notesDirect absorption Frequency modulation technique Tildas Photoacoustic technique Photoacoustic detection Bias Circut Bias-T AppendixGeneral Utilisation What has to be kept in mind before use? Avoid reverse polarity on the input Current and voltage ranges of the Bias-T cir- cuit Unpacking instructions for NS submounts Unpacking NS laser from its transportation box