vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
ACKNOWLEDGEMENT
iv
ABSTRAK
v
ABSTRACT
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF SYMBOLS
xiv
LIST OF APPENDIX
xvi
INTRODUCTION
1.1
Introduction
1
1.2
Flashlamp Driver
2
1.3
Problem Statement
4
1.4
Research Objective
4
1.5
Research Scope
5
1.6
Thesis Outline
6
THEORY
2.1
Introduction
7
2.2
Laser Oscillator
8
2.3
Solid State Laser Materials
15
2.3.1
16
2.4
Nd:YAG crystal
Flashlamp
18
2.4.1
20
Optical Characteristics of Xenon Flashlamp
viii
2.4.2
2.5
2.6.
3
Electrical Characteristics Xenon Flashlamp
22
Flashlamp Driver
23
2.5.1
Pulse Forming Network (PFN)
23
2.5.2
Charging Power Supply (CPS)
28
Triggering Techniques of Flashlamp for Solid-State Laser
31
2.6.1
External Triggering
31
2.6.2
Series Injection Triggering
32
2.6.3
Simmer Mode Triggering
34
METHODOLOGY
3.1
Introduction
35
3.2
Development of Flashlamp Driver
37
3.2.1
Construction of Signal Controller
38
3.2.2
Construction of Simmer Power Supply and
41
Ignition Circuit
3.2.2.1 Development of Ignition Circuit
42
3.2.2.2 Development of Simmer
44
Power Supply (SPS)
3.2.3
Construction of Pulse Power Supply (PPS)
45
3.2.3.1 Development of Capacitor Charging
46
Power Supply (CCPS)
3.2.3.2 Construction of Pulse Shaper Device
3.3
3.4
47
Development of Laser oscillator
49
3.3.1
Xenon Flashlamp
49
3.3.2
Nd:YAG Crystal rod
50
3.3.3
Rear Mirror
50
3.3.4
Output Coupler
51
3.3.5
Flow Tube
52
3.3.6
Ceramic Reflector
53
3.3.7
Cooling System
53
Measurement Equipments
55
3.4.1
Infrared Card
55
3.4.2
Digital Oscilloscope
56
ix
4
High Voltage Probe
57
3.4.4
Photodiode BPX65
57
3.4.5
Energy and Power meter
58
3.4.6
Spectrum Analyzer
59
3.4.7
Digital Voltmeter
59
FLASHLAMP DRIVER AND LASER CHARACTERAZATION
4.1
Introduction
60
4.2
Characterization of FLD
61
4.2.1
Output and Operation of Signal Controller
61
4.2.2
Output Ignition circuit
63
4.2.3
The Output of Simmer Power Supply
64
4.2.4
Output Pulse Power Supply
65
4.2.5
Output Charging Power Supply
65
4.2.6
Emission Spectrum of Flashlamp
66
4.3
4.4
5
3.4.3
Characterization of Nd:YAG Laser
67
4.3.1
Emission spectrum of Nd:YAG Crystal
68
4.3.2
Emission spectrum of Nd:YAG Laser
69
4.3.3
Energy of Laser
69
4.3.4
Pulse duration of Laser
71
Summary
72
CONCLUSION AND RECOMMENDATION
5.1
Conclusion
73
5.2
Recommendation
74
REFERENCES
76
APPENDIX A
82
x
LIST OF TABLE
TABLE NO.
TITLE
PAGE
3.1
List of electronic components for controller circuit
41
3.2
List of components for ignition circuit
43
3.3
Electronics components for simmer power supply
44
3.4
List of components for capacitor charging power supply
47
3.5
List of components for multiple-mesh pulse forming network (mPFN)
48
4.1
Relationship between input energy and laser energy
70
4.2
Relationship between input energy and laser pulse duration
71
xi
LIST OF FIGURE
FIGURE NO.
2.1
TITLE
PAGE
(a) Relative populations in two energy level as given the
9
Boltzmann relations at thermal equilibrium
(b) Inverted population difference required for optical
amplification
2.2
Laser oscillator system for pulse solid-state laser
10
2.3
Typical cavity geometry for solid-state laser
12
2.4
Typical cavity geometry for solid-state laser
13
2.5
Typical cooling system for Nd:YAG laser
14
2.6
Energy level for Nd:YAG atomic system
17
2.7
Absorption band of Nd:YAG laser crystal
18
2.8
Common flashlamp type. (a) Linear. (b) Helical
19
2.9
Spectral emissions from xenon flashlamp in high-current density
21
2.10
Spectral emissions from xenon flashlamp in low-current
21
density cw operation
2.11
Single mesh pulse forming network (PFN) discharge circuit
24
2.12
Multiple mesh pulse forming network
27
2.13
High voltage charging power supply circuits for pulsed laser
30
2.14
External triggering method
32
2.15
Series injection triggering method
33
2.16
Simmer mode circuits for operating flashlamp
34
3.1
Flowchart of the research progress
36
3.2
Block diagram of Nd:YAG laser system
37
3.3
Circuit diagram of signal controller
39
3.4
Block diagram of simmer power supply and ignition circuit
42
3.5
Schematic diagrams for ignition circuit
43
xii
3.6
Circuit diagram of simmer power supply
44
3.7
Block diagram for Pulse Power Supply (PPS)
45
3.8
CCPS circuit diagram
46
3.9
Multiple-mesh pulse forming network (mPFN) circuit diagram
48
3.10
Linear xenon flashlamp
49
3.11
Nd:YAG crystal
50
3.12
Rear mirror a) mirror container
51
b) rear mirror on kinematic mirror mount
3.13
Output coupler a) mirror container
52
b) output coupler on kinematic mirror mount
3.14
The flow tube located in laser pumping chamber
52
3.15
Ceramic reflector of laser chamber
53
3.16
The block diagram of cooling system
54
3.17
Infrared Card for beam detection a) IR card
56
b) Red beam spot as infrared radiation illuminate the IR card
3.18
Tektronix TDS 3054 C Digital oscilloscope
56
3.19
Tektronix P6015A High Voltage Probe
57
3.20
Power/energy meter
58
3.21
WaveStar spectrum analyzer
59
3.22
Digital voltmeter
59
4.1
Output pulse from SIGNAL 2 for ignition circuit
61
4.2
Output pulse from SIGNAL 1 and SIGNAL 3
62
a) output of SIGNAL 1 used to trigger the SCR,
b) SIGNAL 3 (upper trace) is off before SIGNAL 1 is active
4.3
High voltage output pulse of ignition circuit
63
4.4
Output of simmer power supply
64
a) 600 volt dc voltage produced by simmer power supply,
b) Voltage drop across flashlamp during simmer operation
4.5
Voltage waveform of discharging process
65
4.6
Output from CCPS
66
a) Output ripple voltage after bridge rectifier,
b) Channel 1 shows signal to turn off the triac, channel 2 is
an output ripple voltage of CCPS which closed by triac
4.7
Emission spectrum of Flashlamp
67
xiii
4.8
Emission spectrum of Nd:YAG
68
4.9
Spectrum of Nd:YAG laser
69
4.10
Graph of input energy versus output energy of laser
70
4.11
Graph of input energy against pulse duration of laser
72
xiv
LIST OF SYMBOL
K0
–
Flashlamp impedance
V0
–
Charging voltage
Vscnd
–
Secondary voltage
I
–
Current
Ipc
–
Peak current
tr
–
Rise time
tf
–
Fall time
RL
–
Flashlamp resistance
Z0
–
Circuit impedance
l
–
Flashlamp arc length between electrodes
d
–
Internal flashlamp bore diameter
E0
–
Electrical input energy
α
–
Damping parameter
C
–
Capacitance
L
–
Inductance
LC
–
Inductor capacitor network
PFN
–
Pulse forming network
mPFN
_
Multi-mesh pulse forming network
SCR
–
Silicon control rectifier
DC
–
Direct current
AC
–
Alternating current
CCPS
–
Capacitor Charging power supply
CW
_
Continuous wave
SPS
–
Simmer power supply
PPS
–
Pulse power supply
RM
–
Rear mirror
OC
–
Output coupler
xv
FLD
_
Flashlamp driver
IR
_
Infra red
UV
_
Ultraviolet
tp
_
Pulse duration
Zn
_
Network impedance
LT
_
Total inductance
CT
_
Total capacitance
n
_
number of mesh
xvi
LIST OF APPENDIX
APPENDIX
A
TITLE
Basic language program for FLD controller
PAGE
82
xvi