Handbook of Laser Technology and Applications, Volume 1: Lasers: Principles and Operations

Cover
Half Title
Series Page
Title Page
Copyright Page
Table of Contents
Preface
Editors
Contributors
1. Laser Principle: Section Introduction
2. Basic Laser Principles
	2.1 Introduction
	2.2 The Amplifier–Oscillator Connection
	2.3 The Energy Levels of Atoms, Molecules and Condensed Matter
	2.4 Spontaneous and Stimulated Transitions
		2.4.1 Spontaneous Emission
		2.4.2 The Lineshape Function
		2.4.3 Stimulated Emission
		2.4.4 The Relation between Energy Density and Intensity
		2.4.5 Stimulated Absorption
	2.5 Transitions between Energy Levels for a Collection of Particles in Thermal Equilibrium
	2.6 The Relationship between the Einstein A and B Coefficients
		2.6.1 The Effect of Level Degeneracy
		2.6.2 Ratio of Spontaneous and Stimulated Transitions
	2.7 Optical Frequency Amplifiers and Line Broadening
		2.7.1 Homogeneous Line Broadening
		2.7.2 Natural Broadening
		2.7.3 Other Homogeneous Broadening Mechanisms
	2.8 Inhomogeneous Broadening
		2.8.1 Doppler Broadening
		2.8.2 Energy Bands in Condensed Matter
	2.9 Optical Frequency Amplification with a Homogeneously Broadened Transition
		2.9.1 The Stimulated Emission Rate in a Homogeneously Broadened System
		2.9.2 Optical Frequency Amplification with Inhomogeneous Broadening Included
	2.10 Optical Frequency Oscillation—Saturation
		2.10.1 Homogeneous Systems
		2.10.2 Inhomogeneous Systems
	2.11 Power Output from a Laser Amplifier
	2.12 The Electron Oscillator Model of a Radiative Transition
		2.12.1 The Connection between the Complex Susceptibility, Gain and Absorption
		2.12.2 The Classical Oscillator Explanation for Stimulated Emission
	2.13 From Amplifier to Oscillator—the Feedback Structure
	2.14 Optical Resonators Containing an Amplifying Media
	2.15 The Oscillation Frequency
		2.15.1 Multi-mode Laser Oscillation
		2.15.2 Mode Beating
	2.16 The Characteristics of Laser Radiation
		2.16.1 Laser Modes
		2.16.2 Beam Divergence
		2.16.3 Linewidth of Laser Radiation
	2.17 Coherence Properties
		2.17.1 Temporal Coherence
		2.17.2 Laser Speckle
		2.17.3 Spatial Coherence
	2.18 The Power Output of a Laser
		2.18.1 Optimum Coupling
	Acknowledgement
	References
3. Interference and Polarization
	3.1 Introduction
	3.2 Interference
		3.2.1 Wave Coherence
		3.2.2 Coherent-wave Interference
		3.2.3 Interferometers
		3.2.4 Interference between Partially Coherent Waves
		3.2.5 Practical Examples
	3.3 Polarization
		3.3.1 Introduction
		3.3.2 The Polarization Ellipse
		3.3.3 Material Interactions
		3.3.4 Crystal Optics
		3.3.5 Retarding Waveplates
		3.3.6 Polarizing Prisms
		3.3.7 Circular Birefringence
		3.3.8 Polarization Analysis
		3.3.9 Applications of Polarization Optics
	3.4 Conclusions
	Acknowledgements
	References
4. Introduction to Numerical Analysis for Laser Systems
	4.1 Introduction
		4.1.1 Representation of the Optical Beams
		4.1.2 Split-step Method
		4.1.3 Solving the Diffraction Part of the Split-step Method
		4.1.4 Finite-difference Propagation
		4.1.5 Angular Spectrum Propagation
	4.2 Propagation in Homogeneous Media
		4.2.1 Sampling
		4.2.2 Propagation Control
	4.3 Gain and Non-linear Media
		4.3.1 Saturated Beer's Law Gain
		4.3.2 Rate Equation Model
			4.3.2.1 Frantz–Nodvik Solution
			4.3.2.2 Offline Effects
			4.3.2.3 Spontaneous Emission
	4.4 Integration of Geometrical and Physical Optics
	4.5 Dielectric Waveguides
	4.6 Reflecting Wall Waveguides
	4.7 Laser Modelling Software
		4.7.1 Traditional Methods of Modelling
		4.7.2 Selecting Commercial Numerical Modelling Software
		4.7.3 Validation of Software
	References
5. Optical Cavities: Free-Space Laser Resonators
	5.1 Introduction
	5.2 Gaussian Beams
		5.2.1 Conventions and Notation
		5.2.2 Description of Gaussian Beams
		5.2.3 Ray Transfer Matrices
		5.2.4 Gaussian Resonant Modes
	5.3 Stable Resonators
		5.3.1 Two Mirror Resonators
	5.4 Higher-order Modes of Stable Resonators
		5.4.1 Cartesian Coordinates
		5.4.2 Cylindrical Coordinates
		5.4.3 Beam Quality
	5.5 Mode-Matching
		5.5.1 One-lens Approach
		5.5.2 Two-lens Mode-matching
	5.6 Plane Parallel Resonators
	5.7 Unstable Resonators
		5.7.1 Hard-Edged Apertures
		5.7.2 Soft-edged Apertures
	5.8 Distortion Effects
	5.9 Axial Modes
		5.9.1 Stable-resonator Axial-mode Spectral Separation
	5.10 Frequency Selection and Frequency Stability
	5.11 Temporal Resonator Characteristics
	5.12 Fibre Laser Resonators
	5.13 Conclusion
	References
6. Optical Cavities: Waveguide Laser Resonators
	6.1 Introduction
	6.2 Propagation in Hollow Dielectric Waveguides
		6.2.1 Waveguide Mode Expressions
	6.3 Waveguide Resonator Analysis
		6.3.1 The Concept of Resonator Modes
		6.3.2 Waveguide Modes
		6.3.3 Mode Coupling, Coupling Losses and Mode Losses
		6.3.4 Single-mode, Few-mode and Multi-mode Theory
	6.4 First-Order Theory and Its Limits
		6.4.1 Coupling Loss Theory of Single-Mode Waveguide Resonators
		6.4.2 Dual Case I Waveguide Lasers
		6.4.3 Rigrod Analysis for Waveguide Lasers
	6.5 Real Waveguide Resonators: Experiment and Theory
		6.5.1 Distant Mirrors
		6.5.2 Tilted Mirrors and Folded Lasers
		6.5.3 Tunability and Line Selection
		6.5.4 Resonator Mode Degeneracies: Hopping and Hooting
	6.6 Summary
	References
	Reviews
	Other Reading
7. Nonlinear Optics
	7.1 Basic Concepts
	7.2 Mechanisms of Optical Nonlinearity
		7.2.1 Influence of Inversion Symmetry on Second-order Nonlinear Optical Processes
		7.2.2 Influence of Time Response on Nonlinear Optical Processes
		7.2.3 Non-resonant Electronic Response
		7.2.4 Molecular Orientation
		7.2.5 Electrostriction
		7.2.6 Photorefractive Effect
	7.3 Nonlinear Optical Materials
	7.4 Optics in Plasmonic Materials
		7.4.1 Linear Optical Properties
		7.4.2 Plasmonic Mechanisms of Optical Nonlinearity
		7.4.3 Epsilon-Near-Zero Nonlinearities
	7.5 Second- and Third-harmonic Generation
	7.6 Optical Parametric Oscillation
	7.7 Optical Phase Conjugation
	7.8 Self-focusing of Light
	7.9 Optical Solitons
	7.10 Optical Bistability
	7.11 Optical Switching
	7.12 Stimulated Light Scattering
		7.12.1 Stimulated Raman Scattering
		7.12.2 Stimulated Brillouin Scattering
	7.13 Multi-photon Absorption
	7.14 Optically Induced Damage
	7.15 Strong-field Effects and High-order Harmonic Generation
	References
8. Laser Beam Control
	8.1 Transforming a Gaussian Beam with Simple Lenses
		8.1.1 Beam Concentration
			8.1.1.1 Calculating a Correcting Surface
			8.1.1.2 Depth of Focus
		8.1.2 Truncation
		8.1.3 Non-Gaussian Laser Beams
	8.2 Transverse Modes and Mode Control
		8.2.1 Mode Control
		8.2.2 Injection Locking
		8.2.3 Mode Control with Phase-conjugate Mirrors
	8.3 Single Axial Mode Operation
		8.3.1 Theory of Longitudinal Modes
		8.3.2 Selecting a Single Longitudinal Mode
			8.3.2.1 The Ring Laser
		8.3.3 Frequency Stabilization
	8.4 Tunable Operation
	8.5 Beam Shape and Astigmatism in Diode Lasers
		8.5.1 Correcting Astigmatism in Collimators
		8.5.2 Circularizing a Diode Laser
	8.6 Q-switching, Mode-locking and Cavity Dumping
		8.6.1 Q-switching
			8.6.1.1 Rotating Mirrors
			8.6.1.2 Electro-optic and Acousto-optic Q-switching
			8.6.1.3 Passive Q-switching
		8.6.2 Cavity Dumping
		8.6.3 Mode-locking
			8.6.3.1 Active Mode-locking
			8.6.3.2 Passive Mode-locking
			8.6.3.3 Synchronous Pumping
	8.7 Beam Quality—Limits and Measurement
		8.7.1 Frequency and Amplitude Stabilization
		8.7.2 Methods for Suppressing Amplitude Noise and Drift
	8.8 Spatial Filtering
	References
	Further Reading
9. Optical Detection and Noise
	9.1 Introduction
		9.1.1 Nomenclature and Figures of Merit
			9.1.1.1 Signal-to-noise Ratio
			9.1.1.2 Noise-equivalent Power
			9.1.1.3 Detectivity (D) and Specific Detectivity (D*)
			9.1.1.4 Responsivity
	9.2 Photoemissive Detectors
		9.2.1 The Photoemissive Effect
		9.2.2 Photomultipliers
	9.3 Semiconductor Detectors
		9.3.1 Photoelectric Absorption
		9.3.2 pn and Pin Photodiodes
			9.3.2.1 Photovoltaic Mode
		9.3.3 Schottky Diode Detectors
		9.3.4 Avalanche Photodiodes
		9.3.5 Photoconductive Detectors
		9.3.6 Intra-band Detectors or QWIPs
	9.4 Thermal Detectors
		9.4.1 Thermocouples and Thermopiles
		9.4.2 Bolometers and Thermistors
		9.4.3 Pyroelectric Detectors
	9.5 Noise in Photodetection
		9.5.1 Noise in the Optical Signal
			9.5.1.1 Background Noise (Blackbody Radiation)
			9.5.1.2 Photon Noise
		9.5.2 Noise in the Photodetector
			9.5.2.1 Photoelectron Noise
			9.5.2.2 Shot Noise
			9.5.2.3 Generation–Recombination (G–R) Noise
			9.5.2.4 Gain Noise
			9.5.2.5 1/f or Flicker
			9.5.2.6 Temperature Noise
		9.5.3 Noise in the Measurement Circuit
			9.5.3.1 Thermal Noise (Aka Johnson or Nyquist Noise)
			9.5.3.2 Amplifier Noise and Impedance Matching
		9.5.4 Combining Noise Sources
		9.5.5 Bandwidth-related Noise Reduction Methods
	References
	Further Reading
10. Laser Safety
	10.1 Introduction
	10.2 Laser Injuries to the Eyes and Skin
		10.2.1 Injury Mechanisms
		10.2.2 Principal Components and Operation of the Eye
		10.2.3 Laser Injuries to the Eye
		10.2.4 Retinal Injuries
	10.3 Exposure Limits
		10.3.1 Establishing a Threshold Level
		10.3.2 Calculating MPE from Tables
			10.3.2.1 Assessing the Exposure Duration
			10.3.2.2 Dealing with Multiple Pulse Exposures
			10.3.2.3 Small and Extended Sources
		10.3.3 Nominal Ocular Hazard Distance
	10.4 Safety in Product Design
		10.4.1 The Classification Scheme
		10.4.2 Optical Viewing Aids
		10.4.3 Engineering Safety Features on Laser Products
			10.4.3.1 Protective Housing
	10.5 Safety in Practice
		10.5.1 Class-based User Guidance
		10.5.2 Application of Control Measures
		10.5.3 Personal Protective Equipment
			10.5.3.1 Eye Protection
			10.5.3.2 Skin Protection
		10.5.4 Accident Reports
	10.6 Associated Hazards
	10.7 Summary
	References
	Further Reading
11. Optical Components: Section Introduction
12. Optical Components
	12.1 Introduction
	12.2 Optical Design Aspects of Laser Optics
		12.2.1 What and Where Are the Object and Image?
		12.2.2 Size of the Image Waist
		12.2.3 Real Laser Beams
		12.2.4 Multiple Optical Elements and the Use of Ray Tracing
		12.2.5 Evaluation of Aberrations and Diffraction Patterns
	12.3 Surface Phenomena and Thin Layer Coatings
		12.3.1 Reflection at the Surface of a Dielectric
		12.3.2 Vertical Incidence and Effect of a Single Thin Layer
		12.3.3 Multi-layer Coatings and Their Applications
	12.4 Elementary Lens Forms
		12.4.1 The Singlet
		12.4.2 The Dialyte and the Achromat
		12.4.3 Lens Systems with More than Two Elements
	12.5 Use of (Curved) Mirrors
	12.6 Non-focusing Optical Laser-beam Handling and Relaying
	12.7 Thermal Effects in Optical Materials
	12.8 Specifying Optics for Laser Applications
		12.8.1 Tolerances
		12.8.2 Surface Imperfections: Shape Deviations
		12.8.3 Surface Imperfections: Surface Quality
		12.8.4 Communication of Specifications—ISO 10110
	12.9 Manufacture of Optical Components
	12.10 Summary and Conclusions
	References
13. Optical Control Elements
	13.1 Introduction
	13.2 Amplitude Modulation
		13.2.1 Electro-optic Modulators
		13.2.2 Acousto-optic Modulators
		13.2.3 High-power Beams
		13.2.4 Magneto-optic Isolators
	13.3 Scanning and Positioning the Beam
		13.3.1 Mechanical Beam-directing Systems
		13.3.2 Acousto-optic and Electro-optic Scanners
		13.3.3 Diffractive Beam Steering
		13.3.4 Positioning the Beam
	13.4 Controlling the Size and Shape of the Beam
	13.5 Safe Disposal of Unwanted Beams
	References
	Further Reading
14. Adaptive Optics and Phase Conjugate Reflectors
	14.1 Adaptive Mirrors
	14.2 Wavefront Sensors, Reconstruction and Control
	14.3 Non-linear Optical Phase Conjugation
		14.3.1 Four-wave Mixing
		14.3.2 Stimulated Brillouin Scattering
		14.3.3 Photorefraction
		14.3.4 Self-intersecting Loop Conjugators
	References
	Further Reading
15. Opto-mechanical Parts
	15.1 Introduction
	15.2 Requirements and Specifications
	15.3 System Considerations
		15.3.1 Position Description
		15.3.2 Mounting Accuracy
		15.3.3 Mounting Techniques
		15.3.4 Optimization
		15.3.5 Design for Manufacturability
		15.3.6 Testing
	15.4 Materials and Finishes
	15.5 Parts Configuration
		15.5.1 Visualization
		15.5.2 Distortion, Stress and Strain
	15.6 Precision Positioning
		15.6.1 Stages
		15.6.2 Actuators
		15.6.3 Servo-actuator Systems
	15.7 Closure
	References
	Further Reading
16. Optical Pulse Generation: Section Introduction
17. Quasi-cw and Modulated Beams
	17.1 Operation of Solid-state Lasers
		17.1.1 Lamp-Pumped Operation
		17.1.2 Diode-Pumped Operation
		17.1.3 Effects of Thermal Distortion in Solid-state Lasers
	17.2 Operation of CO[sub(2)] Lasers
	17.3 Examples of Quasi-cw or Modulated Beam Applications
	References
	Further Reading
18. Short Pulses
	18.1 Gain Switching
	18.2 Q-switching
		18.2.1 Q-switched cw Pumped Lasers
		18.2.2 Methods of Q-switching
		18.2.3 Mechanical Q-switches
		18.2.4 Electro-optic Q-switches
		18.2.5 Acousto-optic Q-switches
		18.2.6 Saturable-absorber Q-switches
	18.3 Cavity Dumping
	18.4 Mode-locking
	18.5 Master Oscillator with Power Amplifiers
	18.6 Beam Characterization and Pulse Measurement
	References
	Further Reading
19. Ultrashort Pulses
	19.1 Theory of Ultrashort Pulse Generation and Mode-locking
		19.1.1 Active Mode-locking
		19.1.2 Passive Mode-locking
	19.2 Sources of Ultrashort Pulses
		19.2.1 Dye Lasers
		19.2.2 Ti:sapphire Lasers
		19.2.3 Colour-centre Lasers
		19.2.4 Fibre Lasers
		19.2.5 Semiconductor Sources
		19.2.6 Other Common Solid-state Laser Sources
		19.2.7 Sources Based on Non-linear Frequency Conversion
		19.2.8 Sources of Amplified Ultrashort Pulses
	19.3 Pulse Shaping and Dispersion in Optical Systems
		19.3.1 Linear Material Dispersion
		19.3.2 Non-linear Material Dispersion
		19.3.3 Other Sources of Dispersion
		19.3.4 Group-velocity Dispersion Compensation
		19.3.5 Fourier-transform Pulse Shaping
	19.4 Diagnostic Techniques
		19.4.1 Direct Electronic Measurements
		19.4.2 Approximate Methods of Pulse-shape Measurement
		19.4.3 Exact Methods of Pulse-shape Measurement
	19.5 Applications of Ultrashort Pulses
		19.5.1 Imaging
		19.5.2 Ultrafast Chemistry
		19.5.3 Semiconductor Spectroscopy
		19.5.4 Material Processing
		19.5.5 High Field Science
		19.5.6 Other Applications
	References
20. Mode-locking Techniques and Principles
	20.1 Introduction
	20.2 Basic Principles of Mode-locking
		20.2.1 Origin of the Term “Mode Locking”
		20.2.2 Active Mode-locking
		20.2.3 Passive Mode-locking
			20.2.3.1 Basic Principle
			20.2.3.2 Stability of the Circulating Pulse
			20.2.3.3 Start-up Phase
			20.2.3.4 Q-switching Instabilities
		20.2.4 Fundamental vs. Harmonic Mode-locking
		20.2.5 Frequency Combs
	20.3 Saturable Absorbers for Mode Locking
		20.3.1 Parameters of Saturable Absorbers
		20.3.2 Semiconductor Absorbers
		20.3.3 Carbon Nanotubes and Graphene
		20.3.4 Laser Dyes
		20.3.5 Artificial Saturable Absorbers
	20.4 Soliton Mode-locking
	20.5 Mode-locked Solid-state Bulk Lasers
		20.5.1 Initial Remarks
		20.5.2 Picosecond Lasers
		20.5.3 Femtosecond Lasers
		20.5.4 High-power Operation
		20.5.5 High Pulse Repetition Rates
	20.6 Mode-locked Fibre Lasers
	20.7 Mode-locked Semiconductor Lasers
		20.7.1 Mode-locked Diode Lasers
		20.7.2 Mode-locked VECSELs
	20.8 Modelling of Ultrashort Pulse Lasers
	References
21. Attosecond Metrology
	21.1 Introduction
	21.2 General Principles of Attosecond Pulse Characterization
	21.3 Second-order XUV AC/FROG
	21.4 Reconstruction of Attosecond Beating by Interference of Two-photon Transitions (RABBITT)
		21.4.1 Two-Colour IR-XUV Photoionization in the Perturbative Regime
		21.4.2 Spectral Amplitude
		21.4.3 Spectral Phase: RABBITT
		21.4.4 Rainbow RABBITT
	21.5 Isolated Attosecond Pulses
	21.6 Momentum Streaking
		21.6.1 Angular Streaking and Attoclock
	21.7 Complete Reconstruction of Attosecond Beating (CRAB)
	21.8 Phase Retrieval by Omega Oscillation Filtering (PROOF)
		21.8.1 Improved PROOF (iPROOF)
	21.9 Comparison of RABBITT, Momentum Streaking, CRAB and PROOF
	21.10 All-optical Method
	21.11 Other Methods
	21.12 Some Experimental Remarks
	21.13 Principle Component Generalized Projection Algorithm
	21.14 Conclusions and Outlook
	References
22. Chirped Pulse Amplification
	22.1 Introduction
	22.2 CPA Basics
		22.2.1 Original CPA System
		22.2.2 Nd:glass and Ti:sapphire Systems
	22.3 Dispersion Control
		22.3.1 Treacy Grating Compressor
		22.3.2 Martinez Grating Stretcher
		22.3.3 Offner Triplet
		22.3.4 Dispersion Compensation for Optical Elements in the Amplifier
		22.3.5 Grating Alignment Issues
	22.4 Amplification to PW Level Power
		22.4.1 Energy Extraction from CPA Amplifier
		22.4.2 Energy Limitations
		22.4.3 Pulse Duration Limitations
		22.4.4 OPCPA
	22.5 High-intensity Requirements
		22.5.1 Beam Quality
		22.5.2 ASE Issues
	22.6 Concluding Remarks
	References
23. Optical Parametric Devices
	23.1 Introduction
	23.2 Non-linear Frequency Conversion
		23.2.1 Optical Parametric Generation
		23.2.2 Optical Parametric Gain
		23.2.3 Optical Parametric Amplification
	23.3 Phase-matching
		23.3.1 Birefringent Phase-matching
		23.3.2 Quasi-phase-matching
	23.4 Optical Parametric Devices
	23.5 Optical Parametric Oscillators
		23.5.1 Continuous-wave OPOs
			23.5.1.1 Steady-state threshold
			23.5.1.2 Conversion Efficiency
		23.5.2 Pulsed OPOs
			23.5.2.1 Nanosecond OPOs
			23.5.2.2 Picosecond and Femtosecond OPOs
	23.6 OPO Design Issues
		23.6.1 Non-linear Material
		23.6.2 Pump Laser
	23.7 Continuous-wave OPO Devices
	23.8 Nanosecond OPO Devices
	23.9 Synchronously Pumped OPO Devices
		23.9.1 Picosecond OPO Devices
		23.9.2 Femtosecond OPO Devices
	23.10 Summary
	References
24. Optical Parametric Chirped-Pulse Amplification (OPCPA)
	24.1 Introduction
	24.2 Comparison of OPCPA and Lasers
	24.3 Theory
		24.3.1 Parametric Amplification
		24.3.2 Phase-matching
		24.3.3 Saturated Regime – Intensity, Phase and CEP
		24.3.4 Simulations
	24.4 OPCPA Architecture
	24.5 OPCPA in Practice
		24.5.1 Broad Spectral Coverage
		24.5.2 Few-cycle Pulse Duration
		24.5.3 Ultrahigh Power Systems
	24.6 Optical Parametric Synthesizers
	24.7 Summary
	References
25. Laser Beam Delivery: Section Introduction
26. Basic Principles
	26.1 Beam Manipulation
	26.2 Materials for Transmissive and Reflective Optics
	26.3 Beam Quality
	26.4 Beam Requirements at the Workpiece
	26.5 Attenuation
	26.6 Optical Damage
	26.7 Safety
	26.8 Summary
	References
27. Free-space Optics
	27.1 Introduction
	27.2 Laser Beam Propagation and Its Optical Consequences
		27.2.1 Beam Size
	27.3 Computation of Laser Optical Systems
		27.3.1 Location of the Laser Beam Image
			27.3.1.1 Multiple Optical Elements and the Use of Ray Tracing
		27.3.2 Focal Spot Size
		27.3.3 Effect of Aberrations on Image Size and Shape
		27.3.4 Beam Aperturing Requirements and Effects
		27.3.5 Low Beam Quality Sources
		27.3.6 Non-rotationally Symmetrical Laser Beams
	27.4 General Practical Guidelines of Optics for Laser Applications
	27.5 Optics for CO[sub(2)] Laser Systems
		27.5.1 Beam Transport
			27.5.1.1 Articulated Arms
		27.5.2 Lenses for Focusing CO[sub(2)] Laser Radiation
			27.5.2.1 The Single (ZnSe) Lens
			27.5.2.2 Extending the Limits of the Single Lens
			27.5.2.3 Use of Zoom Optics
			27.5.2.4 Thermal Effects in ZnSe Lenses
			27.5.2.5 Use of Artificial Diamond
		27.5.3 Mirror Systems for Use with CO2 Lasers
			27.5.3.1 Angular Field Considerations
			27.5.3.2 The Off-axis Paraboloid
			27.5.3.3 Coma-corrected Optics
			27.5.3.4 General Remarks on Aspherical Mirrors
		27.5.4 CO[sub(2)] Laser Beam Integration for Homogeneous Illumination
		27.5.5 Power Distribution Shaping by Phase Modulation
	27.6 Optics for Lasers Operating in the Visible or Near-IR
		27.6.1 Optical Handling of Fibre-delivered Nd:YAG Laser Radiation
		27.6.2 Lens Design
		27.6.3 Colour Correction
		27.6.4 Optics for Diode Lasers
			27.6.4.1 Classes of Diode Lasers and Applications
			27.6.4.2 Diode Laser Optical Output Properties
			27.6.4.3 Optical Handling of Single-diode Laser Beams
			27.6.4.4 Single-diode Laser-focusing Optics
			27.6.4.5 Optics for Applications of Diode Laser Arrays
			27.6.4.6 Stacks of Diode Laser Arrays
	27.7 Optics for Excimer and Other UV Lasers
		27.7.1 Material Aspects
		27.7.2 Beam Homogenization
		27.7.3 Optics for Imaging a Mask
			27.7.3.1 Design Examples
			27.7.3.2 Photolithography
	27.8 Optics for Other Laser Sources
	27.9 Conclusions
	References
	Further Reading
28. Optical Waveguide Theory
	28.1 Introduction
	28.2 Basic Types of Optical Waveguides
	28.3 Planar and Rectangular Guides
		28.3.1 Planar Guides
		28.3.2 Two-dimensional Guides
		28.3.3 Numerical Methods for Waveguide Analysis
	28.4 Optical fibres
		28.4.1 Description of the Modes and Fields in Optical Fibres
		28.4.2 Modal Birefringence and Polarization-maintaining Fibres
	28.5 Propagation Effects in Optical Fibres
		28.5.1 Attenuation in Optical Fibres
		28.5.2 Dispersion in Optical Fibres
			28.5.2.1 Inter-modal Dispersion
			28.5.2.2 Chromatic Dispersion
			28.5.2.3 Polarization-mode Dispersion
		28.5.3 Non-linear Effects in Optical Fibres and Solitons
	28.6 Mode-coupling
	28.7 Conclusion
	References
	Further Reading
29. Fibre Optic Beam Delivery
	29.1 Fibre Operation
		29.1.1 Total Internal Reflectance Fibres
		29.1.2 Hollow Waveguide Fibres
	29.2 Fabrication
		29.2.1 Fused Silica Optical Fibres
		29.2.2 Chalcogenide, Fluoride and Germanate Glasses
		29.2.3 Crystalline Optical Fibres
		29.2.4 Hollow Waveguide Optical Fibres
		29.2.5 Micro-structured Optical Fibres
	29.3 Implementation
	29.4 Beam Division and Combination
	29.5 Limitations
		29.5.1 Beam Quality and Profile
		29.5.2 Thermal Damage
		29.5.3 Pulsed Laser Damage
		29.5.4 Non-linear Effects
		29.5.5 Mechanical Damage
	29.6 Summary and Future Directions
	References
30. Positioning and Scanning Systems
	30.1 Introduction
	30.2 General Requirements
	30.3 Positioning Systems
		30.3.1 Motion Devices
		30.3.2 Kinematics
		30.3.3 Measuring Devices
		30.3.4 Advanced Positioning Systems and Optical Set-ups
		30.3.5 Influences on Beam Propagation
		30.3.6 Comparison of 3D-positioning Systems
	30.4 Scanning Systems
		30.4.1 Scanning Methods
		30.4.2 Optical Configurations of Scanning Systems
		30.4.3 Polygonal Scanners
		30.4.4 Galvanometer Scanners
		30.4.5 Performance and Accuracy of Scanning Galvanometers
		30.4.6 Mirrors in Oscillatory Scanning Systems
		30.4.7 Piezoelectric Devices
		30.4.8 Acousto-Optic Deflectors
	30.5 Conclusion
	Acknowledgements
	References
	Further Reading
31. Laser Beam Measurement: Section Introduction
32. Beam Propagation
	32.1 Introduction
	32.2 Beam Types
	32.3 Beam Diameter
	32.4 Practical Measurements
	32.5 Propagation Characteristics
	32.6 Beam Transformation by a Lens
	32.7 Alternative Measurement Methods
	32.8 Propagation of Astigmatic Beams
	32.9 Summary
	References
33. Laser Beam Management Detectors
	33.1 Introduction
	33.2 Position-sensitive Detectors
		33.2.1 Resistive Charge Division Sensors
		33.2.2 Strip Detector and Quadrant Detector
	33.3 Multi-pixel Arrays
		33.3.1 Photodiode Arrays
		33.3.2 Charge-coupled Devices as Tracking/Image Sensors
		33.3.3 Complementary Metal Oxide Semiconductor Detectors
	33.4 Fast Response Photodetectors
	33.5 Photodetectors with the Intrinsic Amplification
	33.6 Colour-sensitive Detectors
	33.7 Detectors for the UV Spectral Range
	33.8 Detectors for the IR Spectral Range
	33.9 Common Customizations
		33.9.1 Active Area Sizes, Shapes and Apertures
		33.9.2 Coatings and Filters
	33.10 Photodetector Integration
		33.10.1 Packaging
		33.10.2 Hybrids and Detectors for Fibre-coupled Lasers
	33.11 Future Directions in Detectors Technology and Applications
	References
	Further Reading
34. Laser Energy and Power Measurement
	34.1 Measurement Technique Selection
	34.2 Test Configuration
	34.3 Pyroelectric Sensors
	34.4 Thermopile Sensors
	34.5 Laser Absorbers
	34.6 Semiconductor Photodiode or Optical Sensors
	34.7 Displays
	References
	Further Reading
35. Irradiance and Phase Distribution Measurement
	35.1 Basic Concepts and Definitions
	35.2 Principal Measurement Set-Up
	35.3 Irradiance Distribution Measurement
		35.3.1 Scanning Devices
		35.3.2 Camera-based Systems
	35.4 Phase Distribution Measurement
		35.4.1 Hartmann–Shack Wavefront Sensor
		35.4.2 Interferometers
		35.4.3 Phase Retrieval from Intensity Transport Equations
	35.5 Coherence Measurement
	References
	Further Reading
36. The Measurement of Ultrashort Laser Pulses
	36.1 Ultrashort Laser Pulses
		36.1.1 Measuring the Spectrum
	36.2 The Spectrum and One-dimensional Phase Retrieval
	36.3 The Intensity Autocorrelation
		36.3.1 The Autocorrelation and One-dimensional Phase Retrieval
	36.4 Autocorrelations of Complex Pulses
	36.5 Autocorrelations of Noisy Pulse Trains
	36.6 Third-order Autocorrelations
	36.7 The Autocorrelation and Spectrum—in Combination
	36.8 Interferometric Autocorrelation
	36.9 Cross-correlation
	36.10 Autocorrelation Conclusions
	36.11 The Time-frequency Domain
	36.12 Frequency-resolved Optical Gating (FROG)
	36.13 FROG and the Two-dimensional Phase-retrieval Problem
	36.14 FROG Beam Geometries
	36.15 The FROG Algorithm
	36.16 The RANA Approach
	36.17 Properties of FROG
	36.18 Single-shot FROG
	36.19 Near-single-cycle Pulse Measurement
	36.20 FROG and the Coherent Artefact
	36.21 XFROG
	36.22 Very Simple FROG: GRENOUILLE
	36.23 Measuring Two Pulses Simultaneously
	36.24 Error Bars
	36.25 Other Self-referenced Methods
	36.26 Spectral Interferometry
	36.27 Advantages and Disadvantages of Spectral Interferometry
	36.28 Crossed-beam Spectral Interferometry
	36.29 Practical Measurement Weak and Complex Pulses: SEA TADPOLE
	36.30 Measuring Very Complex Pulses in Time: MUD TADPOLE
	36.31 Single-shot MUD TADPOLE
	36.32 SPIDER
	36.33 Spatiotemporal Pulse Measurement
	36.34 Spatially Resolved Spectral Interferometry: One Spatial Dimension
	36.35 Fibre-based Scanning Spatiotemporal Pulse Measurement: Two and Three Spatial Dimensions
	36.36 Spatiotemporal Measurement Examples: Focusing Pulses
	36.37 Other Spatiotemporal-measurement Methods
	36.38 Spatiotemporal Measurement on a Single Shot: STRIPED FISH
	36.39 Conclusions
	Acknowledgements
	References
Index