Quantum Instruments Cascade Laser Starter Kit User's Manual
Contents
1. Oly 5 gt a Ge M Zz R88 0 O La r 794 p 103 o mM o mM 22 p HLL Pt pa p o o Mn mM Fig 42 TCU151 main board a css Re 1 057 00000 l ye E o CLI iman LP 0000 Riog p P2 RNO 88 o Elo c66 e b ges 3 0 Ojs 2 O oooo O o000o0o RL02 Bha AFFICHAGE 9 Fig 43 TCU151 main board Fig 44 TC51 front panel Starter Kit Instruction Manual CAUTION For the further steps of this check limit the positive current to 1 A and the negative one with 1 2 A by means of the 5 turns potentiometer Temperature limit threshold 21 Measure the voltage on pin 2 of U10 1 Note The value should be 0 7V 70 C If needed adjust it with the trimmer P9 2 22 Power off the instrument Starting the power section of the instru ment 23 Remove the 100 E reference resistor from J8 4 and plug the output cable J8 24 Plug the external cable into the LLH100 and verify that the Pt100 is proprely mounted in the latter 25 Use an external power supply 0 30VDC 3A to simulate the internal power supply 26 Limit the current to 200 mA and connect it to main board J1 connector 3 27 power supply Power on the instrument2. The temperature displayed 2 should be 035 C 47 Set the selector 4 to mode Real C The temperature displayed 2 should fol low the reference temperature Fig 49 TCU151 front panel Fig 50 TCU151 rear panel Chapter 9 Application notes 9 1 Detection techniques 9 1 1 Direct absorption In a direct absorption measurement the change in intensity of a beam is recorded as the latter crosses a sampling cell where the chemical to be detected is contained QC Laser gt gt Chemical Cell m gt Detector Fig 51 Direct absorption technique This measurement technique has the advantage of simplicity In a version of this technique the light interacts with the chemical through the evanescent field of a waveguide or an optical fiber 9 1 2 Frequency modulation technique A M modulation of the beam detected Chemical Cell gt Detector TILDAS In this technique the frequency of the laser is mod aia ulated sinusoidally so as to be periodically in and the laser frequency out of the absorption peak of the chemical to be de tected The absorption in the cell will convert this FM modulation into an AM modulation which is QC Laser gt then detected usually by a lock in techn
3. tion with other instruments without obtain ing prior information and approval from the manufacturer e Never attempt to use spare parts other than those supplied by the manufacturer e If an instrument is to be left unused for any length of time protect the instrument against dust and or humidity 3 4 Environmental conditions e Like any other electrical device the system must not be located near a water tap e The instrument must be kept away from po tential sources of interference e The system must not be exposed to direct sunlight heat dust or excessive humidity use only in a clean laboratory environment e Take care not to spill liquid on an instrument In the event of accidental spillage proceed as follows 1 Switch off the instrument immediately 3 Wipe the instrument down with a dry tissue 2 Unplug the instrument from the mains 4 Check all the electrical functions e Ensure sufficient ventilation of the instrument to prevent overheating 3 5 Compliance and informa tion In the event of operating faults or other technical incidents for which a remedy is not described in this manual please contact the manufacturer or Alpes Lasers SA representative immediately http www alpeslasers ch contacts htm Chapter 4 Description 4 1 Chapter overview For operation of the system the user must pro vide a stabilized DC power supply capable of de This chapter gives a basic descriptio
4. www alpeslasers ch info alpeslasers ch 1 2 Limited waranty Alpes Lasers SA will accept no responsibility for problems arising out of incorrect use of the instrument Under no circumstances will Alpes Lasers SA be held liable for any damage or financial loss imputable to the instrument Copyrighto The reproduction even partially of this document is forbidden No part can be copied in any form and cannot be used edited nor transmitted by any electronic means photocopy photography magnetic supports or other recording processes without the written authorization of Alpes Lasers SA All rights and particularly reproduction translation edition distribution and also industrial property and recording are reserved Printed in Switzerland Chapter 2 General 2 1 Chapter overview This chapter gives basic information on system func tions specifications and documentation 2 2 Generalities The indications in the present Instructions Manual in particular the safety instructions must be com plied with 2 3 Compliance The Quantum Cascade Laser Starter Kit has been designed to meet all current safety at work and op erating requirements 2 3 1 Laser compliance The system described in this manual contains a laser device Depending of the emission power of the laser used in the Starter Kit the classification may change According to the emission power the laser prod uct meets the following requir
5. 1 Power ON OFF switch 2 Period fine 10 turns potentiometer 3 Period range 3 positions switch 4 Pulse duration 10 turns potentiometer 5 BNC 502 TTL pulse 2 output BNC 500 TTL pulse 1 output 7 BNC 500 TTL Trig OUT BNC TTL Gate IN 9 LEMO 00 12VDC output for LDD100 Fig 18 TPG128 front panel Starter Kit Instruction Manual Use 31 6 3 TCU151 command description The internal temperature of the LLH100 is driven by the TCU151 unit The Temperature Controler front and rear pan els are composed of the following items 1 Set Temperature 5 turns potentiometer Allows to set the internal temperature refer ence 2 LCD 3 digits display Used to display ei ther the actual sensor or reference tempera ture current 3 Switch to select which temperature or cur rent signals to display 4 Alarm display LED 5 Alarm reset switch 6 Switch which selects between the internal and the remote temperature reference 7 Setting Current adjustment potentiome ters 8 Power ON OFF fuse combined main switch 9 To LLH100 Amphenol connector for LLH100 temperature control 10 Interlock BNC connector 11 External reference BNC connector 12 Monitoring BNC connector providing the temperature of the sensor as 10mV C signal Fig 19 TCU151 temperature controler front panel Fig 20 TCU15
6. 2 Replacement procedures 8 2 1 Quantum Cascade Laser replacement o 8 2 2 QCL UP and DN position exchange e 8 3 TCU151 temperature controller interlock setting o o gail G neralities ion a rro A a dd At BES 8 3 2 Before beggining interlock setting o 0000000000008 iso Needed m terial qoe marere ci E E E a a A 8 3 4 Procedure interlock setting o ee ee 8 4 Calibaration procedures oaoa 8 4 1 TPG128 calibration edi pe ewe e a es 8 4 2 TCU151 temperature controller calibration o Application notes 9 1 Detection techniques oaoa 9 1 1 Direct absorptioh s ke stes ras dd a a e a e A 9 1 2 Frequency modulation technique TILDAS ooa aaa 9 1 3 Photoacoustic detection 10 Appendix 55 1031 Bias Citcut Blas Ida A a da ee ee aha AA A 55 LOT General a ae A Y a a A AA eh ee he 55 1012 DeSCEPLIOR esti e E A he O Gs AP nk GI ade EA 55 LOL Specifications 0 a ey ce A Se ee Mw e 56 10 14 Utilisation aa La ee ek Bee ae Bee dd ae Se Are Se RS 56 10 2 Unpacking NS laser from its transportation box 0 0 20000000 59 Chapter 1 Identification 1 1 Document Quantum Cascade Laser Starter Kit Instructions Manual Web Version 3 1 02 07 Manufacturer Alpes Lasers SA 1 3 Passage Max Meuron CP 1766 CH 2001 Neuchatel Tel 41 32 7299510 Fax 41 32 7213619 http
7. Ap a a Roe ira 4 8 QCL temperature controller TCU151 oaa a ASST D Scription a 4 4 ae ike Se RAS A A A t A E 4 8 2 Specifications ne A ere PA a a A a Bide ees 4 8 3 Peltier and PT100 connections 2000000000 pee Installation Bl Chapter Overview vice wo 2 6 Gy ee es BA A ee ee a ee ete eR o a 5 2 General Le lia eae Ae td PRE es ee en ai a EA Doo Packing dist 29 to Ma A to AE dr a eR A Le A eS 9 3 1 Standard t s coche RD See ee 5 4 Setting the appropriate AC voltage on TCUI51 o o o e FAR A O O Hb 5 5 Installing the starter Kit oo e 5 5 1 Before beginning seria ee ee a eee Eee ee Bibs 2 Procedure zery fee Ree ete aA A hk tee te ee A Ee Be Use 6 1 Chapter overview aoao 6 2 QCL pulse timing unit command description o 6 3 TCU151 command description i aar a aii a a pe e e e ana ee 64 Laser utilisation 0p a5 0 eee Oe A As e o GAL Overview is mao Bebe da A AR E ee A es 6 4 2 Proceedings 3 ee A a a RE O e ae E 6 5 Interlock utilisation ri o a A a ea Gee y 6 5 1 Before beginning g s 4 dow bdo bd a ee ee Pe A eee be dt ds 6 5 2 Procedure Interlock utilisation o o e Troubleshooting TAO Chapter Over Wi AE E A AA Se oe Se Se A A ed Principle wee aie a re et la e A Beep eee de Gwe Maintenance Sil OVERVIEW gaa eee eek eA be SES alte PP PSS As 8 1 1 How to remove the covers of TCU151 and TPG128 8
8. Cascade Lasers e dl SDeseription 4 4 ta wh ee ee a en ed ee eh eo ida ey a 4 3 2 Geometry of QC lasers e 4 3 3 Specifications a sek EE ee Ra De a a a A e LIA Electrical modelo et ad Boe Ee Lae ee ee ee Be tea ee ak a 4 4 Laboratory Laser Housing LLH100 0 2 0 0000002004 AA Description a8 a1 dl a Bee eal g SERA SE Gre ee Be aE a Boe ee A AGE pee AAs Specifications ke seve teed bb Ele oe OR eR ee RO ee te he 4 4 3 Thermo Electric Cooler TEC and PT100 connections 4 4 4 Measurement Connection 4 5 QCL pulser switching unit LDD100 2 0 0000 0 0 0 0 0000 AO Destription s le te Malle e Hott Ge area de ey ead ad gh Pee neat wok AT laa at dni 2h 4 5 2 Specifications lt 2 2 2 soa el Ea a A ee eo ee o a a 4 6 QCL pulse switching measuring unit a 4 6 1 Generalities 44 wy Gb 2 op DEA eee ae a ee da R 4 6 2 Measured voltages se Aube ee BG Gaede gee ee Bee A ee 4 6 3 Timing data we ie vite ek a aly Bide wedi eee A ete el ME 4 0 4 Laser peak curtent y iio dd e Ee ee Raa Bag eee ee Ee re NDAD voc a Y 4 6 5 Laser peak voltage o ee 4 6 6 Average dissipation elite aa E O AA are ee ad 4 6 7 Accuracy consid rations e e aaa a a A e y a e a 4 7 QCL pulser timing unit TPG128 oaaae dml Degeriptioi idiota dr o ey oai de e A ce as A Re nt E 4 T2 e Specifications Y phn lek Seven e O Rede al ok dy ye BOA
9. Ma IOC 5 c ZA o ese Owe TA Eee ee 8 Ono 10 17 o 11210 flj N oN JM T6 150 a i o MLS o Te oe 3 ag o o yeteeprro a leeks LS 2 elo lle S E 7415123 e ye me o a meleg teedy RJ mborsert R2 OPTIONAL i 4 2 2pF one ol e eee gO e e r e e5 e lt HOO Time ge Nk T3 Pa q e zoria EA za 22 07 99 Y TTL Puls Gen 05 Gate IN g 7 Qe s5 0 Ww pa g x See e 2 Lo eb e e o 100 Z e qe J 750 FTE e dur Bes weecceee Hoose mis J4 8 trig OUT J1 pur 1 our v2 Fig 36 TPG128 main board Starter Kit Instruction Manual Maintenance 8 4 2 TCU151 temperature controller calibration WARNING Keep in mind that during the calibration procedure the instrument is powered on Before beginning 1 Power off the instrument 2 Open the TCU151 top cover 1 to access the TCU151 main board 2 Material needed Voltmeter HP3458A or equivalent Voltage source Keithley SMU237 or equiva lent Precision resistor 100 Ohm 1 or better Cable LEMO 6 poles female 6 bananas fe male LEMO connector LFGG 1B 306 CLAD72Z LEMO handler GMA 1B 065 DG Procedure 5V 5V power supply check CAUTION Do not connect the signal IN 34 V DC connector J1 3 1 Check the input impedance between 5V 5V and GND note The values should be TP1 4 GND 5 gt 5 kQ T
10. PET holder 5 Note If the contact is bad clean the bottom of the submount with grinding paper be care ful of not damaging the bonding wires and the laser facet 12 Place the dry desiccant bag close to the low impedance line plug Only applicable if desiccation is needed and the lasers has been shipped with a desiccant bag Note This operation is preferably performed in a gloves box under dry nitrogen atmosphere if the ambient atmosphere is humid this is not necessary under normal conditions 50 60 humidity 13 Close the cover 2 with the screws 1 Maintenance 39 Fig 27 Replacing the laser Starter Kit Instruction Manual Maintenance 8 2 2 QCL UP and DN position exchange Before beginning 1 Switch the QCL Starter Kit OFF Material needed e 1 set of Allen keys e 1 ohmmeter e 1 FP QCL laser contact plate e 1 pair of tweezers Procedure To exchange the beam of a Quantum Cascade Laser proceed as follows 1 Remove the top cover 2 of the Laboratory Laser Housing LLH100 by unscrewing the screws 1 2 Remove the PET U shaped holder 4 by unscrewing the fixing screws 3 Caution Pay attention NOT to drop the laser 3 Remove the gilded copper contact 6 by unscrewing the back screw 5 4 Install the opposite gilded copper contact 6 by screwing back the screw 5 Fig 28 Removing the laser recptacle Fig 29 Exc
11. and the external Maintenance 50 47uF 16U C36 47UF 16U SN74LS74A LMZ805CT R133 c81 a R101 LJ N U p GOECKELEC Neuch Y SGo73 11 2Q00 o o 1 i a lt Pago ooo Cone xt aro Fie 45 TESI malitbeard y Ae lg o E tH Es gun o 0 OS Zo Sk in HE 5 cat ae l y o R8B 0 o LJ a 2 a cso 2126 Gi O 100E75W O a 2 z LA Baal EEE ERE ERRE rza Ref 053 n ZUC JU cez R8 R4 REO La E 4 a E 4 o Ru8M sA AN mem R96 Sana ARNM U uu Ae 3 En preiz E j wg 8 a aaa lel Bed aL ul ol cor Sano e B R59 S88 ran V mM 89 a o2 5 ooa dis ps Far ee E Ha 2 hae AC Slade R34 L Jnz8n2R27 au ARANA I c14 canso Jess Uua 013 quo 2 5 O ois de e id Eh 1 RER RI ORS a o e O mgen Su ras ail o 2 E Jales J8 gt e o lel ig ras FaR E ES odon E 18988 2 Co Cia d ceo coo BARGA oE I ET aE e gA SEa G ala AC eT a aes Ua E eS uuy amp 4 R67 A ie EREC cJ FUL Dow AOAC 3 Do AUS fri gt C7 Se Lgl lol Fig 46 TCU151 main board Starter Kit Instruction Manual Maintenance 51 Current adjustment 28 Set the
12. selector 3 to mode Setting C and adjust the temperature value to 25 C by means of the Set Temperature 5 tuns portentiometer P8 2 29 On the external power supply rise slowly the voltage to 30 V and the current to 1 5 A gt The tension should stabilize at 30 V Note If the current is too high stop the test and verify the transistors Q1 to Q4 1 and their associated resistors 3s 3 M ao pl i S o ae fo CASIO old Mh n JRioo J8 There might be a soldering problem In this E ae lel o it maa g Gee case fix it and repeat the procedure from step me a S o ooon 10 gt E e cial of lem S85 a l J Ea 48 R49 3 D2 T el AE E Ip Er FE mee JLILJ so 30 Set the selector 3 to mode Real I Cd on ie ee IOI a C64 yl ae o o OP 07 Lite R24 Ras ae d C Sena gt Value displayed lt 1A Ta Rig Laci eae 880 31 Set the selector 3 to mode Real C Fig 47 TCU151 main board gt Value displayed should tend to the defined value 32 Wait for a certain time and check the Peltier temperature with a thermometer
13. switching unit LDD100 operates correctly and safely 4 Low impedance line LBI100 5 Laboratory Laser Housing LLH100 6 CTL100 cable 7 Temperature controller TCU151 8 Power cords 1 Instructions manual Q G A Fig 13 QCL Starter Kit packing list 26 4 Starter Kit Instruction Manual Installation 5 4 Setting the appropriate AC voltage on TCUI51 The TCU151 temperature controller works on 110 120V or 220 240V if the fuse holder is oriented in the ap propriate position Note There are two rates 110 120V 60Hz USA 220 240V 50Hz Europe 5 4 1 Procedure To set the appropriate voltage on the TCU151 tem perature controller proceed as follows 1 Pull out the fuse holder 1 from the socket 2 Verify the orientation of the fuse holder to get the appropriate voltage The arrow on the fuse holder 3 should correspond to the mark on the socket 2 3 Insert the fuse holder 1 into the socket Fig 15 Setting the appropriate AC voltage rate Starter Kit Instruction Manual Installation 5 5 Installing the starter Kit 5 5 1 Before beginning Make sure that the following devices are turned OFF e TPG128 e TCU151 e User DC power supply 5 5 2 Procedure To install the QCL Starter Kit proceed as follows 1 Plug the low impedance line into the LLH100 connector 2 The line connector is coded CAUTION Pay attentio
14. trace of an oscilloscope show ing the L channel minus the B one can get the voltage on the laser This measurement is more accurate than the in formation obtained from the LDD100 measurement unit For more details refer to LDD100 Diagram Block on page Specifications of the measurement connector 19 Starter Kit Instruction Manual Description 20 4 5 QCL pulser switching unit LDD100 4 5 1 Description The switching unit is based on dedicated power MOS FETS with up to 30A current compatibilities and 60V In addition the circuit is limited in power dissipation by the cooling of the unit During op eration the temperature of the case should not ex ceed 60C While powering usual QC diodes these limitations are never reached because the laser has usually much lower power ratings WARNING An important feature of this unit is that both lines going to the laser are HOT i e have a postive voltage respective to the case this feature should be kept in mind when de signing the laser holder This one should be insulated and have a low capacitance lt 100pF towards the ground The QCL pulse switching unit is composed of the following connectors 1 Low impedance connector 2 Drive cable connector 3 Monitoring BNC connector 4 5 2 Specifications Voltage Hio pueceya uceni iyeka max 60 VDC Current Vive ee ee max 30 ADC Repetition rate upto 1MHz limited by average current Ris
15. 00 ns and duty cycles up to 50 the laser may not withstand this The laser shall only be op erated under conditions as specified in the datasheet or by Alpes Lasers directly all other operation may result in destruction of the laser and loss of warranty 4 7 2 Specifications 220V 240V Frequency ee eee eee cs 50Hz 60Hz Output voltage for switching unit 12VDC Output max current for switching unit 150mA Delay between pulses 200 ns to 2 2 us 500 ns to 10 5 ps cos a 5 1us to 105 1 us trigger and logic output signals 500 TTL driver circuit 74128 Maximum duty cycle 50 if larger cycles are needed the LDD100 should be fed by an exter nal 12V power supply not the one provided in the TPG128 or else the fuse in the TPG128 may blow Fig 10 QCL pulser timing unit Limitations Caution The generator can not operate with a 200 ns long pulse at a 200ns repetition interval therefore it is limited in duty factor The following limitations apply TESADODS 300 iii ce seed etc t max 200ns T 30008 ities Ba ea eee t max 200ns WS250NS8 45 dota dia ere ee t max 150ns T 2000S caco cons beds t max 100ns Starter Kit Instruction Manual Description 25 4 8 QCL temperature controller TCU151 4 8 1 Description The TCU151 is used to control the laser s temper ature inside the Laboratory Laser Housing It uses a PT100 sensor to measure the tempera ture of the cold plate
16. 1 temperature controler rear panel Starter Kit Instruction Manual Use 6 4 Laser utilisation 6 4 1 Overview In order to insure a correct use and and an appropri ate lifetime to the laser it is recommended to pro ceed according a specific order as below e Start water flow to cool the LLH100 e Turn on the temperature controller and set the desired temperature e Start the pulse generator e Switch on the power supply 6 4 2 Proceedings To use the Quantum Cascade Laser proceed as fol lows 1 Make sure that the laser has been installed properly see page 38 2 If available turn on the water on the LLH100 module CAUTION If water is not available check the LLH100 module temperature until desired operating temperature is reached The unit has a reduced laser temperature range under reduced heat sinking conditions The unit may become very hot overheat and be destroyed A radiator and possibly a fan might be neces sary to increase the laser operating tempera ture range 3 Turn on the TCU151 instrument 6 Note Set the desired temperature by first push ing the switch 3 to Setting C to display the objective temperature and turn the 5 turn knob 1 to change it Turning the switch 3 to Real C the display shows the present tem perature Note To remote control the LLH100 tempera ture set the switch 5 to external and provide a voltage on the External reference 7 from 6 5V 65
17. 33 Set the selector 3 to mode Setting I 34 Increase the limit of positive current to 3 5A by means of the 1 trimmer 4 located on the front panel 35 Increase the limit of negative current to 5A by means of the I trimmer 5 located on the front panel 36 Change the temperature reference to 25 C and check the displayed current Fig 48 TCU151 front panel Starter Kit Instruction Manual Maintenance 52 Miscellaneous functions testing Temperature limit testing 37 Decrease the temperature limit threshold from 0 7 V to 0 3 V Note For more details see Temperature limit threshold on page 50 38 Increase the temperature reference to 35 C When the threshold is overpassed the red LED 1 in front panel should lit 39 Wait the real temperature drops 10 C below the threshold 40 Reset the instrument with the RESET button 2 The red LED 1 should turn off 41 Reset the temperature limit threshold to 0 7 V Note For more details see Temperature limit threshold on page 50 Monitoring 42 Check the output voltage on the rear in strument BNC connector 5 Note For 35 C the voltage should be 350 mV External reference 43 Plug an external power supply to the Egz ternal Reference BNC connector 6 44 Set the voltage to 3 5 V 45 Set the switch External Internal 3 to External 46 Set the selector 4 to mode Setting C
18. Alpes Lasers Quantum Cascade Laser Starter Kit Instructions Manual Web version CAUTION Before using the Quantum Cascade Laser Starter Kit read this documentation and take special note of all safety instructions Contents Identification Lil Document Rd o A eS ee ee a ee a a 1 2 Limited Waraty 3 24 40 de Sethe Song ea ha Re REE AA SE BEES General 2 1 Chapter Overviews 204 400 Sad oh SLES eee See PEM Lee eee Bo 2 2 Generalities nse 4 a it kee Sa Ee Bemis he ie ee Ae oe ERA ee 2 3 Gomipliance Lct A ee OG Pe AAA ee a ee A 2 3 1 Laser compliance si fa eb a a a eee es Ae GIOSSATY A oS Rata DS RSet aS is i A 2 41 Persons sraa anai a Ba ee ee a ORE A a i oe ey 24 2 PLOGUCE vse a eet te he Bact Bed eg PRE a ele ese oh al Ar ee ee 8 2 5 Typographic conventions ie aei bea a aaa a a a ee ee Safety Instructions 3 5 Chapter overview 2 4 4 44 et e a ED a a a ala ee fund da a ave e 3 2 Aniroduction 5 ss iea ee ee A a E A AAA a E OO RAEE RSS 3 24 Principle aa e A A E S A e ee a 3 2 2 Importance of safety instructions e 3 2 3 Non compliance with the safety regulations o 3 3 General safety instructions 3 4 Environmental conditions 2 2 02 see ee a a e 3 5 Compliance and information Description AT Ghapter Overviews A kb Pad eee ee heed A eee ee he A 4 2 System Composition ia a sa 2 2 0 2 E daa a a ee 4 3 DFB and FP Quantum
19. C to 6 5V 65 C 4 Plug the banana cables into the power sup ply unit and set output voltage to zero and the compliance current to 100mA if pulsing a QCL 32 Fig 21 Starting the TCU151 Fig 22 TCU151 remote control Starter Kit Instruction Manual Use 33 5 Turn the TPG128 ON 8 and set the pulse period to 2 0 and the range to 0 5 to 10 5 us medium corresponding to a period length of about 2 5us or to the values specified on the datasheet or by Alpes Lasers 6 Set the pulse duration 11 to 3 0 corre sponding to a pulse length of about 50ns or to the values specified on the datasheet or by Alpes Lasers 7 Verify laser cabling power meter range set corresponding to the power range of the laser specified in the datasheet zeroed and aligned 8 Turn the HV power supply ON then the TPG128 ON and slowly increase the HV out put voltage but not higher than specified in the datasheet of the laser Fig 23 Starting the TPG128 9 If available monitor the averaged output to avoid overloading the laser In any case place one probe on both the anode and the cathode of the laser and view it with an oscil loscope 10 Subtract the two traces and you get the voltage across the laser that should not be more than the specified max voltage Note The laboratory housing LLH100 makes availa
20. CAUTION Pay attention NOT to drop the laser 3 Remove the laser 4 Hold the laser on the gilded ceramic pads with the tweezers pins along the axis of the largest length of the cop per submount WARNING Take especially care not to touch the active region of the laser or the wire bonds 38 Fig 26 Removing the laser Starter Kit Instruction Manual 4 Install the new laser 4 into the holder using small tweezers 0 5cm aperture 5 Hold the laser 4 on the gilded ceramic pads with the tweezers pins along the axis of the largest length of the copper submount 6 Place it in the receptacle parallel to the window Warning Avoid hitting the laser chip facet on the case it is extremely fragile 7 Place the screws 3 in the PET holder 5 8 Place the PET holder 5 on the two guides 6 on the back of the laser receptacle being careful of maintaining the PET holder higher on the laser side than on the back side 9 Once the PET holder 5 is engaged in the guides push it down until contact with the gilded ceramic pads is established 10 Screw it to the receptacle 11 Verify that the contact is established by measuring with an ohm meter on the LLH100 low impedance plug Note For reproducible measurement be care ful of measuring with the positive probe on the LLH100 connection Note If the contact is bad adjust the plastic screws at the pressing end of the
21. NING Never open this cover Chapter 3 Safety Instructions 3 1 Chapter overview This chapter sets out safety instructions for ensur ing safe and trouble free operation of the system described in this manual 3 2 Introduction 3 2 1 Principle The personnel must have read and understood this documentation before carrying out any activity what soever with the system described in this manual In case of unclear information please contact the manufacturer or Alpes Lasers SA representa tive 3 2 2 Importance of safety instructions All the safety instructions in this manual must be carried out in order to avoid injury to persons or damage to property and the environment Similarly the statutory regulations measures for accidents prevention and protection of the en vironment and the recognized technical rules for safe and appropriate working practices which are in force in the country and place of use of the system must be complied with 3 2 3 Non compliance with the safety regulations Non compliance with the safety instructions statu tory and technical regulations may lead to injuries to persons or damage to property and the environ ment Moreover this will result in loss of warranty 10 Starter Kit Instruction Manual Safety Instructions 3 3 General safety instructions e Never attempt to use a system for purposes other than those detailed in this manual e Never attempt to use a system in conjunc
22. P2 6 GND 5 lt 4kQ 2 Power on the instrument 3 Check the 5V 5V power supply volt age Note The values should be TP1 4 GND 5 4 95 to 5 2 V TP2 6 GND 5 4 95 to 5 2 V 46 Fig 37 Removing the top cover REG2 REGI LMZ905CT LM7805CT J9 NONC Interlock o o0 013 ZN8 ZMY 1 o o 243 RE_1 o gt O 9 EST dS J2 io 700 Oo 0 O Zz a o O ont de greetz IN 2X6UAC o C79 R129 WV l 1 maban o c45 044 0 o R130 REG3 3 LM7805CT cit ULL 47uUF 716V 47uF 716V SN74LS74A ooo Cl Fig 38 TCU151 main board Starter Kit Instruction Manual Maintenance 47 Sensing level and range adjustement 4 Replace the cable connected to J8 4 with A cg ANERE os 07 the 1000 1 reference resistor in the follow MAA o Bh Ae R120 ing way By SUM E Ea a E Ja Rug ae ca 42 L 73s Al ez u2 as u Connect one side of the resistors to pins 1 and JCJ os a Ls 87 Bilbo
23. The generator should be calibrated as followed 1 Verify the 5 V supply 2 During the first test set all potentiometers and adjustable capacitors to their medium val ues 3 Adjust to the potentiometer 50 ns adj 3 in order to obtain a 500 ns long pulse on TP2 2 4 Connect an oscilloscope allowing the mea surement of the signal s period on the output Trig out Fig 33 Removing the top cover 02 07 99 Y TTL Puls Generator TPG 128 ae 5 CAEAD 5 oo mO ci8 10nF 5 S Sm ig ria 6 gt wv lc 00 ae co gt S Q ns aA 18 nF KI D m o e O 2 el ete on fe o j L e he Je pm 55 zme Mie a nO 2 1 daa e sexe A 1 d G A o 4 OTe Ne dsnr e o 3 T e S 90 e R9 mo e mec 3A mk A AMO co a gt Ee a th ney o 0 0 E ieee ee o Z S nue gt je 0 R8 e a G ehe e Ci o T 15 pF oe ee e ES 00 gt meo Or x e o INe e eoo S oe e 3 N ii S mM Zee Joe ree ep CO Se ble E ES N LO mo E le stole g 8 R7 eae El ays elle m 6 8k ne ANO oe peo wee X c N D N 0 Z 10k 64 o Q Tos Y Fig 34 TPG128 main board Starter Kit Instruction Manual Maintenance 5 Choose the range 5 us to 105 ps Pot 10 t
24. a e Ze E Veet 18 Fe Here e oE e a i TPI 2g C TP3 TP4 o gt la E 5k L E F FERC IZA 2p OS e 2 2000600000 c o 1989nF e 0 Z z5 e gt alas TESE 5 FITT Jajor a meeeceee Hooo N n OQ O mor Q0 0720 N Gate IN ss O 7 5 JO 0 Fig 35 TPG128 main board 44 Starter Kit Instruction Manual Maintenance 12 Connect oscilloscope on the output Out1 Load with a 500 Choose a repetition period of about 5 ps 13 Pot 10 turns Duration on 10 Adjust capacitor Max duration 2 to have a output pulse of 200 ns 5 ns 14 Pot 10 turns Duration on 0 Adjust the pot Out Ons adj 1 in order that the output pulse is Ons The pulse is 0 ns long when its shape is triangular with an 1 1 V amplitude half of the maximum value 15 Repeat points 13 and 14 until the val ues are OK 16 Check the output Out 2 check the oper ation of Gate in The input Gate in open high TTL level gate open the output sig nal is present Input Gate in short circuited low TTL level gate closed the output signal is zero 17 Check the 12 V is present on Lemo 00 12 V on the centre connector Le ec 0 t s 0 2 o 14 ue Le o sa L 0 Lo s FSS E p7 22pF 5v GND C ite u N O de cs e ZA Aee n _ 20 M b10 Bee
25. and maintains a pre set tem perature either from a front panel knob or from a user supplied voltage 4 8 2 Specifications Vote ieee ie di 120 240V AC Pr queney csi ea a ers 50 60 Hz Fuse incoada 1 6 A T 220 240V ETE 3 2 A T 110 120V Temperature control range 65 C to 65 C Temperature measurement PT100 4 wires Temperature monitor 10mV C Zout 2002 In addition allow for 15 min warm up of TCUL151 to get stable readings External driving temperature 6 5V to 6 5V 65 C to 65 C Zin 1MQ 4 8 3 Peltier and PT100 connections The rear connector pinout is listed according to the following items 1 Pin 1 Peltier element 2 Pin 2 Peltier element 3 Pin 3 1 PT100 5 Pin 5 Sense PT100 6 1 2 3 4 Pin 4 Sense PT100 5 6 Pin 6 I PT100 7 7 Pin GND Ground Fig 11 TCU151 temperature controller O Fig 12 TCU151 Peltier Connector Chapter 5 Installation 5 1 Chapter overview 5 3 Packing list This chapter describes the installation and the con 5 3 1 Standard items nection of the QCL Starter Kit It also explains the T f operating checks before the normal use The standard starter Kit is supplied with the fol lowing items 5 2 General 1 QCL pulse timing unit TPG128 The setup procedures outlined below must be fol 2 CPL100 cable lowed meticulously to ensure that QCL Starter Kit 3 QCL pulse
26. asing the temperature of the laser sub mount and base in total If operation at only a fixed wavelength is needed this should be adjusted with the overall tem perature control e Too high a DC Bias current can immediately destroy the laser due to catastrophic thermal roll over Therefore set up of the Bias current has to be done only by instructed personnel and after checking with Alpes Lasers SA for allowed parameter ranges otherwise warranty will be lost What has to be kept in mind before use e All use of a Bias T on a specific QC laser has to be accepted by Alpes Lasers SA before otherwise all warranty will be lost e The Bias T should never be used at the high est specified current or output power other wise the risk of thermal roll over failure is im minent e Ifoptical output power can be monitored this should be used during set up of the Bias T to make sure that thermal roll over is not reached Temporary increasing of the pulse current must always result in increased optical power out put otherwise the DC Bias current is already too high Starter Kit Instruction Manual Appendix e As arule of thumb the overall dissipated power sum of DC Bias current dissipation and pulse current dissipation must never be higher than the average dissipated power given by the high est current voltage temperature combina tion specified in the datasheet Take into account that the average dissipated power for a gi
27. ble two outputs giving access to these voltages see documentation 11 Set the desired pulse and period length as specified in the datasheet or by special agree ment with Alpes Lasers Starter Kit Instruction Manual Use 6 5 Interlock utilisation The temperature controller is designed with an built in interlock 1 This function is activated when a fault occurs on the TCU151 controller over temperature over current etc The interlock is by default a NC Normally Close relay contact CAUTION It is also possible to set the Inter lock as a NO Normally Open contact For more details about the settings see the procedure on page 42 6 5 1 Before beginning In order to recover the temperature controller from an interlock event please pay attention about the following points e Locate the fault which caused the interlock and fix it e Wait until the temperature driven by the TCU151 is lower than the maximum 6 5 2 Procedure Interlock utilisation To reset the temperature controller from an inter lock event proceed as follows 1 Press the RESET button 3 on the TCU151 front panel lt gt The interlock is reset and the red LED ALARM 2 should be off 34 Fig 24 Interlock BNC connector Fig 25 Reseting the interlock Chapter 7 Troubleshooting 7 1 Chapter overview This chapter sets out troubleshooting instructions for ensuring safe and trouble free op
28. de Real C 2 Check the power supplies 5V and 5V The error should be within 50 mV Starter Kit Instruction Manual General Procedure effects style The procedure effects are described by using the following symbol Example 1 Click on the Delete Sample icon The message Do you really want to delete the sample appears Cross references style This style is used to help the personnel to find other information about the current subject Example See page x y Troubleshooting style The complete description with the problem the possible cause and the solution will be shown like described below Problem Possible cause y Solution List of items style This style is used to give a list of items Example e item 1 e item 2 e item 3 Starter Kit Instruction Manual General Note style Used when the personnel attention must be drawn to a particular operation or information Example Note The laboratory housing LLH100 makes available two outputs giving access to these voltage Caution style Used to prevent the personnel from any danger or hazardous situation Non compliance with such instructions may lead to damage parts or environ ment Example CAUTION Take care about Warning style Used to prevent the personnel from any impor tant danger or hazardous situation Non compliance with such instructions may lead to death or serious injury Example WAR
29. ds carrying the bonding wires The pads are yellow on top due to a layer of gold and white around it and on the sides colour of the ceramic If these pads are placed upwards the vertical for the laser is the same as the observer vertical direction If there are two ceramic pads present they are named as follows Looking onto the front facet with the laser placed as described above the pad left of the laser chip is called DN for DOWN the one on the right of it UP If no configuration is specified the DN pad is used Never place the laser upside down since this will damage the bonds connecting the pads to the laser and possibly the laser itself The laser chips mounted on NS submounts pro vided separately from a LLH100 are supplied in a round plastic box For removing the laser from it please follow the instructions as described in ap pendix appendix 10 2 p 59 13 Ay Te Fig 3 ST submount 65 Lu el 1 ip TH l l 0 3 3 ol 2 2 2x BEA 1 mes l a we ON a Ela l 9 5 El 1 3 lo sxase 4x Fig 4 NS submount Starter Kit Instruction Manual Description 14 4 3 3 Specifications Far field elliptical FWHM Vertical tesis hac rd a Ok ai a aaa a a adtta ada inion ss Mel Mattern lee 60 Horizontal iia E al M
30. e A D duty cycle dependent peak transistor drain oltage respective to VHT lt e UPI 1 2 average internally reshaped drive volt age respective to ground e UPT 1 2 average of a 37ns fixed length pulse respective to ground 4 6 3 Timing data Pulse frequency calculation UPT can be used to calculate the pulse frequency as follows E 2UPT vpiow f J fo VPhigh YPlow Where fo is a frequency constant vpjow and UPhigh are the TTL pulser voltage limits Actual values fo ns UPlow 0 01V UPhign 5V 21 Starter Kit Instruction Manual Description Duty cycle calculation UPI can be used to calculate the duty factor as follows 2UPI Vplow df VPhigh YPlow with UPlow and UPhigh AS above To get the real duty cycle df must be corrected as follows 2UPI ow de frppdf fron ee to compensate for systematic errors in the LDD100 Actual value is frpp 1 1 4 6 4 Laser peak current The laser peak current can be calculated by the measurement of the current through the series re sistor Rs This is provided by the values ULL and UD which are rectifier outputs To correct for the duty cycle the rectifier values have to be taken into account with the following formula for a correction factor Rd iS LF Ecd where Rds and Rc are resistors in the rectifier circuit de is the duty cycle calculated as in the preceding paragraph Actual values are Rds 10kQ and Re 10MQ The corrected
31. e with the Set Tem perature potentiometer Fig 40 7 to 5 C The temperature reference signal B3 should be lt 4 3V 13 Check the switch range by setting the Temperature Reference at 2 C and 2 C B7 5V and 5V B6 5V and 5V 14 Check the output voltage of the transis tors The signals on R78 and R81 should tog gle simultaneously with the inversal signals on R79 and R80 CAUTION The signals B6 and B7 2 must never be at OV simultaneously Other wise there is a risk of short circuit Maintenance 48 Ll c7 2330282923322 338 R130 REGS U13 2y TOAT D A OSD E cres E J cS A eee ase ull 47UEASU 47UF OU SN74L574A Ct JJ 012 UU N C r3 8 3 9 de cs 0 il c35 036 o C cer gt mn Rez gt E Bie ca a ES Lol TPE a 100uF710u Drg 5 5USW R86 R43 E o o o o o A om N LM3LID C85 C86 po C47 R93 N gg Au uu Let SSL E a 6 og csof C Sjrize R JE INPRAAA O o o E Jrz Re Far 208 nn CM PS C Frise ES a ae E OUUU g E LILe cat J opt m eE el o RS R66 C77 R52 R58 zn T Ee L _JRiz m NA en d m us E res IMM ai cert J TI imeti2c3 8 eee J ll a D5 R91 A e UsTME1 2 mes to C 2 b
32. ed holder in order to effective the contact with the laser by means of the POM fixing screws y Check the connections on the LLH Measure the input resistance with an ohm meter between the Laser connector and the Base receptacle connector 36 Chapter 8 Maintenance 8 1 Overview This chapter describes all procedures of mainte nance and calibration for the QCL starter Kit The procedures described herein must be performed by personnel trained on the electronic field with ac ceptance by Alpes Lasers otherwise the warranty will be lost Note The TTL Pulse Generator TPG128 and the Temperature Controller TCU151 are calibrated in factory 8 1 1 How to remove the covers of TCU151 and TPG128 Pull off the light gray plastic pieces of the side of the front and back plates Lift off the light gray plastic shades form the side of the box which gives access to the screws holding the top and bottom covers 37 Starter Kit Instruction Manual Maintenance 8 2 Replacement procedures 8 2 1 Quantum Cascade Laser replace ment Before beginning 1 Switch the QCL Starter Kit OFF Material needed e 1 set of Allen keys e 1 ohmmeter e 1 QCL laser e a pair of tweezers Procedure To replace the Quantum Cascade Laser proceed as follows 1 Remove the top cover 2 of the Laboratory Laser Housing LLH100 by unscrewing the screws 1 2 Remove the PET U shaped holder 5 by unscrewing the fixing screws 3
33. ements LASER BEAM DO NOT STARE INTO BEAM CLASS I LASER PRODUCT CLASS I Emission power lt 10 mW CLASS IIIb Emission power gt 10 mW Fig 1 Class I laser compliance Starter Kit Instruction Manual General 2 4 Glossary The following terms among others are used in this Instructions Manual 2 4 1 Persons Personnel Personnel refers to all persons who carry out any activity with the instrumentation and meet the manufacturer s requirements about personnel to run those activities and have been therefore authorized 2 4 2 Product QCL This is the Quantum Cascade Laser manufac tured by Alpes Lasers SA CH 2001 Neuch tel Starter Kit Instruction Manual General 2 5 Typographic conventions The following styles are used in this manual Description style This style used in relation with a number in il lustrations figures is preceded by the correspond ing number Example 1 First item 2 Second item 3 etc Commands style All software commands buttons function keys windows icons options tabs check boxes select boxes items menus tool bars sections and fields used in this documentation will be shown with a bold italic font Example The Exit command permits to leave the pro gram Procedure style The steps of a procedure to be carried out step by step by the personnel are preceeded with num bers placed in brackets Example 1 Set the selector 4 to mo
34. eration of the Quantum Cascade Laser Starter Kit system 7 2 Principle 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 y Check the cabling v Replace the laser if necessary The DC power supply is NOT floating y 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 y Loose the laser fixture device 35 Starter Kit Instruction Manual Troubleshooting 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 y Check the polarity of the connection The polarity is right It draws too much current and the power meter is misaligned y Reduce the current at the maximum specified for the operating temperature y Check power meter alignement and scale The QCL laser is not used with the LLH and is grounded y Check that there is no short circuit on the circuit The laser does not draw current There is no contact with the laser y Check that the gilded copper contact is present and properly mounted y Tighten the PET U shap
35. h chs edi Baden bees Wo poten ek SRS a 40 Operating temperature Might vary for each laser but generally located in the range from 30 C to 30 C Caution Before operating the laser at different temperature than specified in the datasheet please contact Alpes Lasers SA or a representative Damages resulting from a non respect of temperature operat ing range without approval from Alpes Lasers SA will led to a loss of warranty Submount size ST mountings sve es wha A ie aie Daa a ae os 19x 7x 2mm NS mounting ic sates le tarot ari aN 19 x 7 x 2 5 top of the ceramic pads mm Typical laser position Over the submount centered laterally 2 0 0 0 cece eee ences 0 2 mm Inside the sub mount top surface 0 cece cent ene e nee e ene ennes 0 03 mm Laser emitting facet troagh reedita taa a ee eee eee een ee eens 0 005 0 030 x 0 004 mm Starter Kit Instruction Manual Description 15 4 3 4 Electrical model The QCL can be modelised in a RC circuit R1 Electrical model characteristics Ti se aoe t The values given below apply for a 10um laser wavelength C 4 C2 Fig 5 Electrical model of QCL Note Voltage and resistor values may vary according to the type of laser RA Miata diia wedi che an 10 to 200 when a voltage of 4 to 6 Volts is applied Ria des gi tei hte ARO A A 2 to 40 up to 10 12 Volts A ohevgu vacua 10 to 200 over 12 Volts after wh
36. hanging the laser Starter Kit Instruction Manual 5 Place the screws 3 in the PET holder 4 6 Place the PET holder 4 on the two guides 5 on the back of the laser receptacle 6 being careful of maintaining the PET holder higher on the laser side than on the back side 7 Once the holder 4 is engaged in the guides push it down until contact with the gilded ce ramic pads of the laser is established 8 Screw the PET holder 4 to the receptacle 6 9 Verify that the contact is established by measuring with an ohm meter on the LLH100 low impedance plug Note For reproducible measurement be care ful of measuring with the positive probe on the LLH100 connection Note If the contact is bad adjust the plas tic screws 7 at the pressing end of the PET holder 4 10 Place a dry desiccant bag close to the low impedance line plug Only applicable if desiccation is needed and the lasers has been shipped with a desiccant bag Note This operation is preferably performed in a gloves box under dry nitrogen atmosphere if the ambient atmosphere is humid this is not necessary under normal conditions 50 60 humidity 11 Close the cover 2 with the screws 1 Maintenance 41 Fig 30 Placing the PET U shaped holder Starter Kit Instruction Manual Maintenance 42 8 3 TCU151 temperature con troller interlock setting 8 3 1 Generalities The interlock is located on the
37. hapter 10 Appendix 10 1 Bias Circut Bias T 10 1 1 General The Bias T allows to apply a constant DC cur rent to the laser in addition to the pulsed current therefore a Bias T is useless in CW mode The current is drawn from the external user supplied power supply through the laser This current can be controlled electrically Since tuning of a QC laser is done by changing the temperature of the active zone the DC Bias cur rent can be used to control the emission wavelength of the laser via its heating effect The Bias T there fore allows for electrically controlled rapid scanning of the emission wavelength The achievable shift is of the order of 0 1 with a Bias frequency of up to 100Hz 10 1 2 Description The circuit included in the LDD100 pulser unit is controlled by the twisted black and yellow wires of the control cable with the DSUB 9 plug They correspond to the shield and center of the IN con nector in the former case positive voltage on yellow wire This version has no monitor connection Low Impedance Line VDC User Power Supply GND Control IN Monitor MONTI LDD100 Fig 53 Bias circuit diagram block 55 Starter Kit Instruction Manual Appendix 10 1 3 Specifications Bias frequency Up to 100 Hz Achievable shift 00 000s 0 1 Input voltage Ujn eee eee eee 0to3 V Input
38. ia A mri 200 a 2 the other side to pins 3 and 4 ute Sn Ea a wi nana 824 Lius 913 eco E y y a O LU 5 Measure the voltage on Zn3 R10 3 0 3651 i an E E a o U himuo A O Note The value should be E a 2 7I a Chios J8 S ct po fee as oo6n0 O V 1 22 to 1 25V o PE E i del 7 o ace i i i all AE Ao TT UU E lee 1 en o El e a g E42 us enine an 6 Measure the voltage at the intersection of g gM eT ae 2 y y R19 R35 5 tee arai 882 ua o c l p Pe E Note The value should be V 100mV ad s2 Moe mo hoe o R124 justable with the potentiometer P1 2 Le o a 2 J CJ Note If the range is too small replace the 900000000000 khs s Jo T a o o 16144 LF resistor R1 1 1 3kQ with 1 4k0 000000000000 O E 1 3 7 Set the selector 9 to display Real C P7 Pa to o oesO 8 Adjust the trimmer P6 6 in order to ob tain the value of 000 C on the screen 8 E 9 Vary the Temperature Reference by using the Set Temperature 5 turns potentiometer 7 located on the front panel Note The range displayed should be O74 to 074 Fig 40 TCU151 front panel Starter Kit Instruction Manual Temperature Reference offset adjustment 10 Adjust B13 3 to 0 000 with P3 4 11 Set the temperature with the Set Tem perature potentiometer Fig 40 7 to 5 C The temperature reference signal B13 should be gt 4 3V 12 Set the temperatur
39. ich the laser no longer operates A E E A dhe ants 100pF capacitor between the anode and the cathode CQ ia die oats Gh iS diia lt 100pF depending on your mounting of the laser Starter Kit Instruction Manual Description 16 4 4 Laboratory Laser Housing LLH100 4 4 1 Description The Laboratory Laser Housing is a Thermo Electric cooled box which encapsulates the Quantum Cas cade Laser The internal temperature is controlled by a PT 100 sensor and heat is dissipated by air or water The LLH100 is designed to ease the laser installa tion or replacement LLH100 external view description The Laboratory Laser Housing is composed of the following items 1 ZnSe coated laser beam window 2 Peltier connector and PTC sensor 3 Low impedance connector 4 Cooling water flow fittings recommended flow 0 25 1 min 10 20 C 5 Monitoring base receptacle connector 6 Monitoring laser connector Fig 6 Laboratory Laser Housing front and rear view Starter Kit Instruction Manual Description 17 LLH100 internal view The Laboratory Laser Housing includes the follow ing items 1 LLH100 top cover 2 PET U shaped holder 4 1 2 3 Gilded copper contact UP and DN 4 Laser 5 5 Laser receptacle 4 4 2 Specifications Maximum Peltier current Highest recommended temperature due to Peltier limitations 80 C Window Diameter 2005 12 7 mm Clea
40. ing falling edge typical 8ns max 12ns Minimum pulse width 16ns typical 20ns Maximum pulse width Lys limited by power supply Support power given by TPG128 Trigger IN eeror iere yaaa kt TTL 500 Propagation delay typical 35ns lt 40 ns SIZE edo ON 90 x 130 x 50 mm WARNING The connection between the laser and the QCL pulse switching unit is floating It must not be connected with the ground Fig 9 QCL pulser switching unit front and rear view Starter Kit Instruction Manual Description 4 6 QCL pulse switching measuring unit 4 6 1 Generalities The measuring circuit contained in the LDD100 provides information about various laser pulse pa rameters peak voltages supply voltages duty cy cle frequency They are only estimated values since exact measurement of short and strong pulses with diodes and averaging circuitry is difficult Keep in mind that you should always measure the voltages on the LLH100 if you need accurate time and voltage data see final paragraph How ever these data are useful for monitoring and surveil lance purposes and to give a rough estimation of the current parameters 4 6 2 Measured voltages e UHV 1 2 of the average voltage respective o VHT user supplied high voltage er e ULH 1 2 of the average laser anode voltage respective to VHT o a LL duty cycle dependent peak laser cathode oltage respective to VHT lt
41. ique The advantage of the TILDAS technique is mainly 7 its sensitivity First of all under good modula w tion condition an AC signal on the detector is only gt x present when there is absorption in the chemical cell Secondly this signal discriminates efficiently against slowly varying absorption backgrounds For this reason this technique will usually work well for narrow absorption lines requiring also a monomode emission from the laser itself 53 Fig 52 Frequency modulation technique TILDAS Starter Kit Instruction Manual Maintenance 54 9 1 3 Photoacoustic detection In the photoacoustic detection the optical beam is a c modulation of Detection of the periodically modulated in amplitude before illumi the laser amplitude acoustic wave at w nating the cell containing the absorbing chemical The expansion generated by the periodic heating of the chemical creates an acoustic wave which is ce Chemical Cell gt oe detected by a microphone dio The two very important advantages of photoa Fig 53 Photoacoustic technique coustic detection are e a signal is detected only in the presence of absorption from the molecule e no mid IR detectors are needed For these reasons photoacoustic detection has the potential of being cheap and very sensitive How ever ultimate sensitivity is usually limited by the optical power of the source C
42. ly siase sadly ET Saal l 8 Remove the laser from the rods 3 Unscrew the bottom of the box AX Note Hold the laser carrier as indicated by the red arrows and avoid to touch the facet or the wire bonds Fig 54 Unpacking instructions for NS submounts 9 The laser is ready to be installed
43. main board Note By default the interlock is set to NC Nor mally Close contact 8 3 2 Before beggining interlock set ting 1 Switch the instrument OFF 2 Unplug the power cord 3 Remove the cover 1 to acces the main board 2 8 3 3 Needed material e 1 set of screwdriver e 1 tweezer 8 3 4 Procedure interlock setting To set the type of interlock proceed as follows 1 Locate the J9 Interlock connector 2 Place the associated jumper according to the type of desired interlock Note The common pin is on the center 4 and by placing the jumper on a side defines the interlock type as for a NC contact jumper on pins 4 and 5 for a NO contact jumper on pins 3 and 4 Fig 31 Opening the TCU151 cover coo tage fama ag E A J9 ZI Interlock i O 043 Fig 32 J9 Interlock connector Starter Kit Instruction Manual Maintenance 43 8 4 Calibaration procedures 8 4 1 TPG128 calibration Generalities The present section describes procedure to be car ried out for particular calibration of the TPG128 Before beginning 1 Switch the instrument OFF 2 Remove the cover 1 3 Switch the instrument ON WARNING Keep in mind that dur ing the calibration the instrument is alive powered on Needed material e 1 set of screwdriver e 1 oscilloscope e 1 voltmeter Procedure calibration
44. n about the con nection s polarity The laser must be floating from ground for both anode and cathode 2 Plug the low impedance line into the QCL pulser switching unit low impedance output 1 paying attention for the polarity A Fig 16 Installing the Quantum Cascade Laser Starter Kit 28 Starter Kit Instruction Manual 3 Plug the cable 3 onto the LDD100 4 4 Plug the 12VDC connector 1 into the TPG128 9 5 Plug the trigger BNC connector 2 into the TPG128 9 Out 1 or Out 2 outptut CAUTION The unit must be floating 6 Plug the banana cables 8 red and black into the DC power supply unit 7 Plug the LEMO connector 6 onto the LLH100 module 5 and the connector 7 onto the TCU151 unit 8 Plug the cooling water tubing if available CAUTION If no water cooling is avail able pay attention to the LLH100 module case temperature and be careful of either reducing heat dissipation or providing air cooling to the unit Installation Fig 17 Connecting Starter Kit 29 Chapter 6 Use 6 1 Chapter overview This chapter describes how to use the QCL Starter Kit It also explains the functionalities of the TPG128 and the Temperature Controller TCU151 6 2 QCL pulse timing unit com mand description The Quantum Cascade Laser is controlled by the QCL pulse timing unit TPG128 The TPG128 front panel is composed of the following items
45. n of the Quan livering DC current that corresponds to the laser tum Cascade Laser Starter Kit system and its com peak current multiplied with the specified duty cy position cle at the specified LDD100 voltage refer to the datasheet of the laser 4 2 System Composition The Quantum Cascade Laser Starter Kit is made CAUTION up of the following items Do not lift TCU151 or TPG128 only on the top cover since this might loosen the connection be 1 Laboratory Laser Housing LLH100 tween the cover and the chassis 1 2 Temperature Controller TCU151 3 QCL pulse switching unit LDD100 4 4 QCL pulser timing unit TPG128 Fig 2 Quantum Cascade Laser Starter Kit Starter Kit Instruction Manual Description 4 3 DFBand FP Quantum Cascade Lasers 4 3 1 Description Quantum Cascade Lasers QCL are unipolar lasers emitting in the mid infrared from 4 to 17 microns The laser is a ridge of InGaAs and AllnAs grown on InP providing gain and a Fabry Perot cavity in order to build the laser oscillation up Distributed Feedback DFB Quantum Cascade Lasers are then obtained by adding a grating forcing the laser to emit at the target wavelength 4 3 2 Geometry of QC lasers Mountings Lasers exist in two different packages e ST mounting 1 e NS mounting 2 Axes of QC lasers The vertical direction is the so called growth direc tion Device are mounted on a copper carrier which has one or two ceramic pa
46. ono Lol VaR d T E c12 m n cas mim B88 as Std aa a gt rea E R100 a du i ceal aa o jest ny of DE Fadel R34 122882827 911 823 a 2 REI Ree da obtain d Tcse ae ee e070 uz o o o c25 AN ese E x CY GOECKELEC Neuchatel o mo a E SGo 3 11 2Q00 q op tae E E Rie JB o o ES 9 0 Rae 03 C J o 0000 a Y o 0 2N3 Externe J6 onyo O Hat C mLa Laa o k ELESSE al J J al Jo gi Penta cae ae 599 630 eb Va FI ras oT ella E R47 D4 J R50 O C rss Hea SUR E nE 5 WU Te REZE CI ne asa 4s ne JA an EJ cee UU Load 2 o OP 07 R24 R20 del Co LE gt bL Heet a on tet R48 Rei C53 2585 wl IT o LM6144 ae RS o PE 2 LJ H TI SW_2 o R105 RIIA o o Lona CUL E opi eras gt 7 5 P3 33 pr Fig 41 TCU151 main board Starter Kit Instruction Manual Oscillator check 15 Measure the frequency on the pin 7 of U13 1 Note The value is 28KHz 3KHz Current Voltage ratio adjustment 16 Adjust the trimmer P4 6 in order to read B4 0 6V 4 17 Set the selector 5 to mode Setting I The LCD screen should display 1 00 A Note If it is not the case adjust it with P2 2 18 Adjust the trimmer P4 in order to read B4 3 0 V The LCD screen should display 5 00 A Note If it is not the case adjust it with P2 2 Example 0 6 V 0 99 A and 3V gt 4 99 A 19 Set the switch on the front panel to mode Setting I 20 Repeat steps 2 and 4 for P5 7 and B5 3 Maintenance 49
47. r aperture 0 11 mm Coating ZnSe 3 to 12 ym Temperature measurement PT100 4 wires Fig 7 Laboratory Laser Housing internal view Starter Kit Instruction Manual Description 4 4 3 Thermo Electric Cooler TEC and PT100 connections The pin 1 is recognised by a circle around it and a thin noon ended circle starts from pin one and turns around the pins until pin 6 1 Pin 1 Peltier element 2 Pin 2 Peltier element 3 Pin 3 I PT100 5 5 Pin 5 Sens PT100 4 Pin 4 Sens PT100 6 Pin 6 I PT100 Specifications of the Peltier connector HGG 1b 306 CLLPV Cable plug reference LEMO FGG 1b 306 CLAD72Z Plastic protection for the cable LEMO GMA 1b 065 DG Cable Diameter unn ia 5 8 mm Section 6 x 0 25 mm 2 x 0 25 for each Peltier connections or Diameter 00000 7 2 mm Section 10 x 0 25 mm 2 x 3 x 0 25 for Peltier connections 18 Fig 8 Front view of the Peltier connector Starter Kit Instruction Manual Description 4 4 4 Measurement connection These connections give access to the voltage on the laser The L connection is connected AC coupled to the cathode of the laser through a divider by ten The end of cable must be 502 terminated for accu rate measurement The B is connected the same to the anode of the laser Base Receptacle By using the math
48. t ages show nonlinearities especially around 13V and therefore the voltage may seem to saturate at a certain current for certain lasers In addition the change in laser impedance around threshold can generate remarkable nonlinearities compared to the above calculations If you need accurate values proceed as follows 1 Measure laser peak voltage frequency and duty cycle using a two channel oscilloscope connected to the LEMO jacks of the LLH100 in differential mode 2 Measure average current into the laser us ing the value given by the HV supply or by an attached RMS ampermeter 3 Calculate peak current by dividing average current by the duty cycle Starter Kit Instruction Manual Description 24 4 7 QCL pulser timing unit TPG128 4 7 1 Description The QCL pulser timing unit is designed to control the QCL pulser switching unit It provides TTL pulses on 50 on two indepen dent outputs The pulse duration is adjustable from 0 to 200ns The interval between pulses can be ad justed between 200ns and 105ys in 3 ranges A TTL level Gate in input and Trigger out output have also been included The trigger pre cedes the output pulse by about 100ns The QCL pulser timing unit includes the 12VDC power supply needed by the QCL pulser switching unit by means of a Lemo 00 connector with the 12V on the centre wire Warning Although the pulser system is capable of delivering pulses with lengths up to 2
49. urns Period on 10 Adjust the adjustable capacitor max 105 us adj 4 in order to obtain a 105 us long period 6 Pot 10 turns Period on 0 Ajust the pot Period min adj 1 in order to have a period of 5 ps 7 Repeat steps 5 and 6 in order to obtain 105 1 ys and 5 0 1 us for the two settings of the pot Period 8 Choose the range 0 2 us to 2 2 us Pot 10 turns Period on 10 Adjusts the capaci tor maz 2 2 us adj 2 in order to obtain a period of 2 2 ps 9 10 turn pot Period on 0 Check that the period is 200 ns If it is not the case re adjust the pot 50 ns adj 5 in order to obtain 200 20 ns In general it is not possible to go below 210 ns 10 Choose the range 0 5 us to 10 5 us Pot 10 turn Period on 10 Adjust capacitor maz 10 5 us adj 3 in order to have a period of 10 5 ps 11 Pot 10 turns Period on 0 Check the period is 0 6 0 0 1 ps T OA 00 1 NE Y 3 4 5 M L LN O 5 00 a e E Bo UL G a OO Y 5V GND i O A eel 3 0 i oe Mee CIA a o TPs ay ay ze 7 0 1010 7 a LE LE o 1210 fl pos AIM TRE Tur av E TE e a 9 AA o o n e eo o Ma 4 2 LO 7AST33 isles LS z 6 E meeeeoe Rd PEyyyy yy amp R2 OPTIONAL BD 2 2ph MO y zi e P e
50. values for the peak laser cathode and transistor drain voltage are then given as fol lows ULLpeak pULL Uds U Dpeak pUD Uds where Uds is the voltage drop across the recti fier diode actual value Uds 0 25V Finally the laser peak current is then given by ULLpeak UDpeak Ipeak Rs E where Rs is the series resistor actual value Rs 0 850 22 Starter Kit Instruction Manual Description 4 6 5 Laser peak voltage The laser peak voltage is given by Upeak 2ULH ULL peak where ULL peak is the corrected peak value of ULL as calculated in the previous paragraph 4 6 6 Average dissipation The average thermal dissipation of the laser is given by P UneakLpeak de where Upeak and fpeax are the peak values of laser voltage and current as calculated in the pre vious paragraphs and dc is the corrected duty cycle 4 6 7 Accuracy considerations The duty cycle corrected is accurate to about 5 for pulse lengths in the range 50ns to 150ns and pulse periods in the range lus to 10us Especially for short pulses the accuracy can deteriorate to over 10 These calculations and data are compared to the pulse lengths measured via the BNC connec tor of the LDD100 The TTL pulses generated by the TPG128 are always longer due to losses in the LDD100 Since the other calculations depend on the duty cycle data they are in general even less accurate The rectifier circuits used to measure the peak vol
51. ven pulse current I pulse voltage U and duty cycle d is given by d x I x U whereas the dissipated power due to a Bias current IB is given by IB x U U is the voltage on the laser but it is safe for this calculation of Bias current dissipation to use the voltage on the LDD pulser input Current and voltage ranges of the Bias T cir cuit Since the input stage of the Bias T is a bipo lar transistor applied voltage must be higher than about 0 6V to start Bias current The in put stage has maximum voltage limit of 2 6V but the laser itself may be destroyed at lower Bias T control voltage already therefore the maximum rating has to be checked with the abovementioned rules and together with Alpes Lasers SA The monitor output if available allows mea surement of applied DC Bias current Its volt age divided by 1002 gives Bias current In general Bias current can be in the range of 0 1A but this must be checked with Alpes Lasers SA before CAUTION Avoid reverse polarity on the input Starter Kit Instruction Manual 10 2 Unpacking NS Appendix laser from its transportation box Instructions for QCL unpacking 1 Remove the box from the package Den pt Piles Laser 2 Remove the security band Note In case the band is not present or intact please call Alpes Lasers SA before opening 7 Remove the base 5 Flip the box siase7 sad
52. voltage threshold 0 6 V Input frequency Fin oooo oo o 0 to 1 kHz Input impedance Zin ooooocoorccco 1000 Output Uron MA 25 V Output impedance Zmon lt lt lt lt 102 Ratio Umon A ere ned ee 10mV mA 10 1 4 Utilisation The current into the sink must not exceed too much a value given by the laser specifications as follows The largest allowed peak current of the laser from the LI curves multiplied by the respec tive duty cycle gives the upper limit of the mean laser current Imax Lyomaxx d The sum of the Bias current J and the actu ally applied mean laser current Ip q should be limited by the upper limit of the mean laser current ly T Lord lt Lpmaxxd The Bias T itself has a limit at Umon 2 5V or Uin 3V Note If higher voltages are applied excessive heating of the Bias T may occur and destroy the laser 56 Starter Kit Instruction Manual Appendix Dangers and disadvantages of using a Bias T circuit e Since a Bias T only allows to heat the laser the emission wavelength can only be increased or emission wavenumber decreased and out put power will decrease with increased Bias current due to the additional heating This means that the laser should be operated initially at lowest possible temperature e Heating of the active zone will increase ther mal stress of the laser therefore the expected lifetime will decrease more rapidly compared to incre
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