Alpes Lasers QUANTUM CASCADE User manual

QUANTUM CASCADE LASER USER’SMANUAL
Version number 3.1.8
c
2016 ALPES LASERS SA

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COPYRIGHT INFORMATION
This manual can be copied and distributed under the following conditions: the work
must be attributed in the manner specified by the author or licensor, and cannot be
altered or transformed.
WARRANTY
1. The customer must control the incoming deliveries and inform ALPES LASERS
about incomplete shipments or defective goods within 30 days after delivery.
ALPES LASERS warrants that the products respect the performance set forth in
the quotation, provided that the product is used according to ALPES LASERS
recommendations described in the datasheet included in the shipment.
2. Defective products will be replaced during the 2 years following delivery.
3. All other claims such as purchase refund, product reconditioning or damage of
any nature, be it direct, indirect or consequential, are expressly ousted.
4. The customer is aware of laser products being devices with a statistical rate of
failure. Depending on the use made of this product, it is the customer’s respon-
sibility to use caution, redundancy and appropriate technical measurement to
ensure the final product’s proper operation.
5. In case of discrepancy between the manual and terms written in the order con-
firmation, the order confirmation prevails.
CONTACT INFORMATION
Avenue des Pâquiers 1
2072 St-Blaise
Switzerland
Telephone: [phone]
Fax: [phone]
Email: inf[email protected]
Web site: http://www.alpeslasers.ch
c
2016 SA iii

DOCUMENT VERSION
This is Version 3.1.8 of the manual, published on March 11th, 2016, superseding
version 3.1.7 of the manual, published on October 16th, 2015. The following modifi-
cations have been applied since the publication of version 3.0:
Date of publication Version number Changes
11/3/2016 3.1.7 Change of address
16/10/2015 3.1.7 Modified § 5.4 - removed TC-3 control comments
11/09/2015 3.1.6 Modified § 5.4 after software improvements
26/08/2015 3.1.5
Corrected fig. 5.8 and added informa-
tion on high duty cycle operation
07/08/2015 3.1.4 Added § 5.4
14/05/2014 3.1.3 Clarified Menu navigation in § 5.1.1
29/04/2013 3.1.2 Updated table 5.2
07/03/2013 3.1.1 Added §C.1
28/01/2013 3.1.0
§ 1.3.2 was added and § 1.3.1 is depre-
cated.
§3.3.7 and 3.3.8 have been added.
§5.1 has been added.
Various references to temperature con-
trollers have been updated throughout
the manual.
24/05/2012 3.0.1 § 1.3.3, the LDD voltage is typically be-
low the ratings, not above.
iv QCL user’s manual v3.1.8

Preface
This manual is a reference tool for personnel using ALPES LASERS QCLs and elec-
tronic equipment. Its purpose is to provide the customer with sufficient information to
carry out normal installation and operating procedures. It is not intended to replace
or supersede any local directive. Table 1 gives a summary of the content of each
chapter.
CAUTION:
All personnel must read and understand this manual before attempting
to operate ALPES LASERS QCLs or electronic device. Failure to follow
safety instructions could result in death or serious injury.
Chapter Content
1. Overview General overview of ALPES LASERS QCLs and Starter
Kit components.
2. Safety Information for ensuring safety during the installation, op-
eration and maintenance of ALPES LASERS QCLs and
electronic equipment.
3. Installation Prerequisites, guidelines and list of connections for the
installation of ALPES LASERS equipment.
4. QCL operation Principle of operation of QCLs, ALPES LASERS datasheet
and QCL parameters.
5. Starter Kit Operation Procedures for setting up the Starter Kit and operating a
QCL.
6. Technical specifications Technical specifications and drawings of ALPES LASERS
QCLs and electronic equipment.
7. Maintenance Procedures for exchanging a laser in the LLH housing
and calibrating ALPES LASERS electronic equipment.
Appendices Informations and procedures for advanced users.
Table 1.: Structure of the QCL User’s Manual.
v

Typesetting conventions
•Table 2 gives a list of the acronyms used in this manual.
•Aboxed item indicates a hardware setting on an electronic device.
!"
#$%
&'( )*+,-./-01,-
$'
2## 2*+,-.#03/,.#-01,-
224
5#"
567
5(
8&9
:72 :;*<=;>.7*+?*/,.2*+,-
(6
67@
6&7
6'A :72.B;)+,-.=0>0<C.;<0=
!?-3<D> 8EE0?0*).<*>, 8=F,-.<*>,
!<=0G",E),?=03<.?3*=0<C
#0+=-0H;=,/.$,,/%*?I.J)*+,-K
&L=,-<*).B3M,-.+;BB)D
$*H-DG',-3=.J)*+,-K
:72.B;)+,-.+M0=?F0<C.;<0=
2*H3-*=3-D.2*+,-.43;+0<C
5,C*=01,.#0EE,-,<=0*).",+0+=*<?,
5,C*=01,.6F,->*).73,EE0?0,<=
+?-,M,/.)*+,-.+;H>3;<=
8-0C0<*).&N;0B>,<=.9*<;E*?=;-,-
?)*>B,/.)*+,-.+;H>3;<=
6,> B ,- * =; -,. 7 3< =-3 ) .@< 0=
6F,->3&),?=-0?.733),- ',)=0,-.?33),-
662.';)+,.A,<,-*=3-
Table 2.: Acronyms used in this manual.
vi QCL user’s manual v3.1.8

Contents
Preface v
1. Overview 1
1.1. ALPES LASERS products . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.1. QCL parameters and performance . . . . . . . . . . . . . . . . 2
1.1.2. QCL geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.3. QCL mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. QCL housings and packages . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1. Laboratory Laser Housing (LLH) . . . . . . . . . . . . . . . . . 5
1.2.2. High Heat Load (HHL) Housing . . . . . . . . . . . . . . . . . . 6
1.2.3. TO3 Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3. Starter kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3.1. Temperature Controller (TCU) . . . . . . . . . . . . . . . . . . 10
1.3.2. Temperature Controller (TC-3) . . . . . . . . . . . . . . . . . . 11
1.3.3. Laser Diode Driver (LDD) . . . . . . . . . . . . . . . . . . . . . 12
1.3.4. TTL Pulse Generator (TPG) . . . . . . . . . . . . . . . . . . . 14
1.3.5. S-2 QCL Pulser . . . . . . . . . . . . . . . . . . . . . . . . . . 14
1.4. Peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
1.5. Fields of applications . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.5.1. IR.................................. 16
1.5.2. THz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2. Safety 19
2.1. General safety considerations . . . . . . . . . . . . . . . . . . . . . . 20
2.2. Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2.1. Symbols and labels . . . . . . . . . . . . . . . . . . . . . . . . 22
2.3. Health hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.3.1. LASER radiation hazard . . . . . . . . . . . . . . . . . . . . . . 23
2.3.2. Electrical hazard . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.3.3. Environmental hazard . . . . . . . . . . . . . . . . . . . . . . . 23
3. Installation 25
3.1. Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.1.1. Environmental conditions . . . . . . . . . . . . . . . . . . . . . 26
3.1.2. Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.2. Receiving procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
vii

3.3. Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.1. LLH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.3.2. HHL ................................ 34
3.3.3. TO3 ................................ 35
3.3.4. LDD ................................ 36
3.3.5. CTL cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.3.6. CTLm cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.3.7. TC-LLH cable . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.3.8. TC-HHL cable . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.3.9. CPL cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.3.10. CIL cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3.11. Connection procedure . . . . . . . . . . . . . . . . . . . . . . . 42
4. QCL Operation 45
4.1. Principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.2. ALPES LASERS datasheet . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.3. QCL spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.3.1. Temperature and current tuning . . . . . . . . . . . . . . . . . 48
4.3.2. Linewidth of pulsed single-mode DFB QCLs . . . . . . . . . . . 51
4.3.3. Linewidth of CW single-mode DFB QCLs . . . . . . . . . . . . 51
4.3.4. Bandwidth of multi-mode FP QCLs . . . . . . . . . . . . . . . . 52
4.4. I-V curve and emitted power . . . . . . . . . . . . . . . . . . . . . . . 52
4.4.1. Maximum operating current . . . . . . . . . . . . . . . . . . . . 54
4.4.2. Maximum LDD voltage . . . . . . . . . . . . . . . . . . . . . . 55
4.4.3. Other DFB QCL plots . . . . . . . . . . . . . . . . . . . . . . . 56
4.5. Beam Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5. Starter Kit Operation 59
5.1. Temperature Controller TC-3 . . . . . . . . . . . . . . . . . . . . . . . 60
5.1.1. Quick Start Procedure . . . . . . . . . . . . . . . . . . . . . . . 60
5.2. Temperature Controller Unit (TCU) . . . . . . . . . . . . . . . . . . . 63
5.2.1. TCU startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2.2. Internal/external mode . . . . . . . . . . . . . . . . . . . . . . 65
5.2.3. TCU interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3. TTL Pulse Generator (TPG) . . . . . . . . . . . . . . . . . . . . . . . 67
5.3.1. Internal and external modes . . . . . . . . . . . . . . . . . . . 68
5.3.2. Setting the pulse parameters . . . . . . . . . . . . . . . . . . . 70
5.3.3. Maximum duty cycle . . . . . . . . . . . . . . . . . . . . . . . . 71
5.4. S-2 Pulser (S-2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.4.1. Internal Control . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.4.2. External Control . . . . . . . . . . . . . . . . . . . . . . . . . . 76
5.5. General procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.5.1. QCL startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.5.2. QCL shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
viii QCL user’s manual v3.1.8

6. Technical specifications 83
7. Maintenance 91
7.1. Laser installation in LLH housing . . . . . . . . . . . . . . . . . . . . . 92
7.1.1. Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.1.2. Contact set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
7.1.3. Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
7.1.4. UP and DN contact exchange . . . . . . . . . . . . . . . . . . 97
7.2. Calibration procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.2.1. TCU interlock level setting procedure . . . . . . . . . . . . . . 99
7.2.2. TCU calibration . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.2.3. TPG calibration . . . . . . . . . . . . . . . . . . . . . . . . . . 109
A. QCL theory and application notes 113
A.1. QCL wavelength range . . . . . . . . . . . . . . . . . . . . . . . . . . 113
A.2. QCL electrical response . . . . . . . . . . . . . . . . . . . . . . . . . 114
B. Operations for advanced users 115
B.1. Direct QCL voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
B.2. Soldering wire bonds from laser chip to submount . . . . . . . . . . . 116
B.3. Bias-T circuit for pulsed lasers . . . . . . . . . . . . . . . . . . . . . . 117
B.3.1. Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
B.3.2. Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
B.3.3. Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
B.3.4. Gas concentration measurement . . . . . . . . . . . . . . . . . 118
B.4. CW modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
B.4.1. External power supply protection . . . . . . . . . . . . . . . . . 120
C. Cryogenic operation of QCLs 123
C.1. LN2 Dewar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
C.1.1. Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
C.1.2. Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
C.2. Others . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
c
2016 SA ix

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