Quantum Instruments Cascade Laser Starter Kit manual Troubleshooting, Principle

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Chapter 7

Troubleshooting

7.1Chapter overview

This chapter sets out troubleshooting instructions for ensuring safe and trouble-free operation of the Quantum Cascade Laser Starter Kit system.

7.2Principle

The personnel must have read and understood this documentation before carrying out any activity what- soever with the Quantum Cascade Laser Starter Kit. In case of unclear information, please contact the distributor.

The power supply reaches max cur- rent for a very low voltage

-The low impedance line or the QCL is shorted to ground.

√Check the cabling.

√Replace the laser if necessary.

-The DC power supply is NOT ﬂoating.

√Change the cabling in order to leave the laser ﬂoating.

-The laser tightening device is too tight- ened and the QCL laser is shorted to ground.

√Loose the laser ﬁxture device.

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Contents Quantum Cascade Laser Starter Kit Instructions Manual Web versionContents Installation TroubleshootingMaintenance Overview UseAppendix Identiﬁcation DocumentLimited waranty ManufacturerGeneral Chapter overviewGeneralities ComplianceGlossary PersonsProduct PersonnelCommands style Procedure styleTypographic conventions Description styleProblem Procedure eﬀects styleSee page x-y Troubleshooting style Possible causePage Safety Instructions Importance of safety instructionsNon-compliance with the safety regulations IntroductionGeneral safety instructions Environmental conditionsCompliance and informa- tion Description System CompositionDFB and FP Quantum Cascade Lasers If no conﬁguration is speciﬁed, the DN pad is usedDescription Geometry of QC lasersSpeciﬁcations Electrical model characteristics Electrical modelLaboratory Laser HousingLLH100 LLH100 external view descriptionLaboratory Laser Housing internal view LLH100 internal viewSpeciﬁcations of the Peltier connector Thermo-Electric Cooler TEC and PT100 connectionsSpeciﬁcations of the measurement connector Measurement connectionQCL pulser switching unitLDD100 QCL pulser switching unit front and rear viewQCL pulse switching measuring unit GeneralitiesMeasured voltages Timing dataLaser peak current Duty cycle calculationLaser peak voltage Average dissipationAccuracy considerations Trigger and logic output signals Ω TTL driver circuit QCL pulser timing unit TPG128QCL temperature controllerTCU151 Peltier and PT100 connectionsInstallation Chapter overview Packing listGeneral Standard itemsSetting the appropriate AC voltage on TCU151 Procedure110-120V, 60Hz USA 220-240V, 50Hz Europe Installing the starter Kit Before beginningConnecting Starter Kit Use QCL pulse timing unit com- mand descriptionTCU151 command description TCU151 temperature controler front panelLaser utilisation OverviewProceedings Starting the TPG128 Procedure Interlock utilisation Interlock utilisationTroubleshooting Power supply reaches max cur- rent for a very low voltageDC power supply is not ﬂoating PrincipleLaser draws current but gives no light Laser does not draw currentQCL laser is not used with the LLH and is grounded There is no contact with the laserMaintenance How to remove the covers of TCU151 and TPG128Overview Replacement procedures Quantum Cascade Laser replace MentFacet on the case, it is extremely fragile + LLH100 connectionQCL UP and DN position Exchange Exchanging the laserIf the ambient atmosphere is humid this is HumidityTCU151 temperature con Troller interlock setting Procedure interlock settingBefore beggining interlock set Ting Needed materialCalibaration procedures Procedure calibration1 TPG128 calibration GeneralitiesTPG128 main board TPG128 main board 2 TCU151 temperature controller calibration Procedure +5V/-5V power supply checkSensing level and range adjustement = 1.22 toTemperature Reference oﬀset adjustment Current/Voltage ratio adjustment SettingOscillator check LCD screen should display 1.00 a7V = 70 C If needed, adjust it with the trimmer P92 Starting the power section of the instru MentCurrent adjustment → Value displayed ≤ 1A→ Value displayed should tend to the deﬁned value Miscellaneous functions testing Temperature Limit testing → The temperature displayed 2 should be 035 CThreshold on → The red LED 1 should turn oﬀApplication notes Detection techniquesDirect absorption Frequency modulation technique TildasPhotoacoustic detection Photoacoustic techniqueAppendix Bias Circut Bias-TGeneral Utilisation What has to be kept in mind before use? Current and voltage ranges of the Bias-T cir- cuit Avoid reverse polarity on the inputUnpacking NS laser from its transportation box Unpacking instructions for NS submounts