Handbook of Laser Technology and Applications, Volume 4: Laser Applications: Medical, Metrology and Communication

Cover
Half Title
Series Page
Title Page
Copyright Page
Table of Contents
Preface
Editors
Contributors
1. Lasers in Metrology: Section Introduction
2. Fundamental Length Metrology
	2.1 Introduction
	2.2 Basics
		2.2.1 Evolution of the Metre – Definition and Realization
		2.2.2 Laser Interferometry
		2.2.3 Homodyne Laser Interferometry
		2.2.4 Heterodyne Laser Interferometry
		2.2.5 Interferometer Set-ups
		2.2.6 Grating Interferometers
	2.3 Frequency Stabilized Lasers
		2.3.1 He-Ne laser Stabilized to the Gain Profile
		2.3.2 Iodine-Stabilized He-Ne Laser at λ = 633 nm
		2.3.3 Stabilized Frequency-Doubled Nd:YAG Laser at 532 nm Wavelength
		2.3.4 Frequency-Stabilized Diode Lasers
	2.4 Practical Issues
		2.4.1 Refractometry
		2.4.2 Interpolation
		2.4.3 Accuracy Limits of Laser Interferometers
		2.4.4 Applications of Laser Interferometers
	2.5 Multiple Wavelength Interferometry
		2.5.1 Gauge Block Calibration
		2.5.2 Interferometric Distance Measurements
	References
3. Laser Velocimetry
	3.1 Laser Velocimetry
		3.1.1 Laser Doppler Velocimetry
			3.1.1.1 Fringe Model
			3.1.1.2 Doppler Model
			3.1.1.3 Transmitting Optics
			3.1.1.4 Receiving Optics
			3.1.1.5 System Configurations
			3.1.1.6 Signal Processing
			3.1.1.7 Data Processing
	3.2 Particle Image Velocimetry
		3.2.1 Basic Principles
		3.2.2 Choice of Laser
		3.2.3 Three-Velocity Component PIV
	3.3 Doppler Global Velocimetry
	3.4 Phase Doppler Techniques
		3.4.1 Basics of Light Scattering
		3.4.2 Measurement Principle
		3.4.3 Implementation
	3.5 Application Issues
	3.6 Future Directions
	References
	Articles
	Further Reading
4. Laser Vibrometers
	4.1 Introduction
	4.2 Basic Principles of Laser Vibrometry
	4.3 Solid-Surface Vibration Measurements
		4.3.1 Frequency-Shifting and/or Direction Ambiguity Removal
		4.3.2 Optical Geometry/Interferometer
		4.3.3 Doppler Signal Processing
		4.3.4 Solid-Surface Scattering of Laser Light: Laser Speckle
	4.4 Limitations of Use
		4.4.1 Laser Speckle Effects
		4.4.2 Measurements on Rotating Targets
		4.4.3 Scanning Laser Vibrometers, Impact Measurements and Practical Considerations
	4.5 Measurement of Angular Vibration Velocity
		4.5.1 Introduction
		4.5.2 The Laser Torsional or Rotational Vibrometer
		4.5.3 Measurements within a Rotating System
		4.5.4 Practical Considerations and Examples of Use
	References
5. Electronic Speckle Pattern Interferometry (ESPI)
	5.1 Introduction
	5.2 Principle of ESPI
		5.2.1 Introduction
		5.2.2 Description of the Technique
		5.2.3 Principle of Fringe Formation
		5.2.4 Fringe Interpretation: Relationship between the Phase Change Δ (x,y) and Deformation Components u, v, and w....
		5.2.5 Measurement of Out-of-Plane and In-Plane Deformation
	5.3 Evaluation of the Interference Phase in ESPI
		5.3.1 Temporal Phase-Shift Technique
			5.3.1.1 4 +4 Algorithm
			5.3.1.2 4 +1 Algorithm
			5.3.1.3 Other Temporal Phase-Shift Algorithms
			5.3.1.4 Generation of a Phase-Shift
		5.3.2 Spatial Phase-Shift Technique
			5.3.2.1 Spatial Phase-Shift Method Based on Multi-Pixel Calculation
			5.3.2.2 Spatial Phase-Shift Method Based on Carrier-Frequency and Fourier Transformation
	5.4 Applications of ESPI
		5.4.1 Applications of Temporal Phase-Shift ESPI
			5.4.1.1 Out-of-Plane and In-Plane Deformation Measurement and Non-destructive-Test
			5.4.1.2 Measurement of Three-Dimensional Deformations and Strain
		5.4.2 Applications of Spatial Phase-Shift ESPI
			5.4.2.1 Out-of-Plane and In-Plane Deformation Measurement under a Continuous Loading
			5.4.2.2 Simultaneous Measurement of 3D-Deformations under a Single Loading
		5.4.3 Applications for Dynamic Measurements
			5.4.3.1 Time-Averaged Method with a Refreshed Reference Frame
			5.4.3.2 Stroboscopic Method
			5.4.3.3 Double-Pulse Method
			5.4.3.4 Further applications of ESPI
	5.5 Conclusions
	References
6. Optical Fibre Hydrophones
	6.1 Introduction
	6.2 Basic Principles
		6.2.1 Sonar System Requirements
		6.2.2 Brief History
		6.2.3 Interferometric Hydrophone Basic Principles
	6.3 Optical Fibre Interferometry
		6.3.1 Interferometer Configurations
		6.3.2 Lasers
		6.3.3 Modulation Properties
		6.3.4 Noise Properties
		6.3.5 Summary of Characteristics of Lasers Used in Interferometric Fibre Optic Sensors
		6.3.6 Components
	6.4 Acoustic Interactions
		6.4.1 The Basic Transduction Mechanism
		6.4.2 Coated Fibres
		6.4.3 Mandrel Hydrophones
		6.4.4 Hydrophone Responsivity with Depth
		6.4.5 Hydrophone Response at Higher Frequencies and Directionality
		6.4.6 Sensitivity to Other Effects
		6.4.7 Practical Hydrophone Designs
	6.5 Signal Processing
		6.5.1 Passive Interrogation Schemes
		6.5.2 Noise Sources and Phase Resolution
		6.5.3 Dynamic Range
		6.5.4 Digital Techniques
	6.6 Optical Systems and Multiplexing
		6.6.1 The FDM Technique
		6.6.2 TDM Architectures
		6.6.3 TDM Architectures Analysis
		6.6.4 Large-Scale Array Architectures
		6.6.5 Overcoming Polarization-Induced Signal Fading
		6.6.6 Future Trends in Optical Hydrophone Technology—Fibre Laser Sensors
	6.7 The Optical Geophone
		6.7.1 The Basic Transduction Mechanism
		6.7.2 Alternative Geophone Designs
		6.7.3 System Configurations for Geophone Use
	6.8 Application Studies
	References
	Further Reading
7. Laser Stabilization for Precision Measurements
	7.1 Basic Spatial and Spectral Characteristics of Lasers
	7.2 Advantages of Frequency Stabilization
	7.3 Applications of Frequency-Stabilized Lasers
		7.3.1 Frequency-Stabilized Lasers as Sources for Dimensional Interferometry
		7.3.2 Interferometry for Gravitational Wave Detection
		7.3.3 The Determination of Fundamental Constants
	7.4 Gas-Cell-Absorption-Based Stabilization Techniques
		7.4.1 Frequency Stabilization of a He-Ne Laser to the Gain Curve
		7.4.2 Frequency Stabilization Based on Doppler-Limited Absorption
		7.4.3 Frequency-Stabilization-Based Doppler-Free Spectroscopy
		7.4.4 Frequency-Stabilized Lasers Referenced to Iodine, Rubidium and Acetylene
	7.5 Evaluation of Frequency Stability and Reproducibility
	7.6 Cavity-Stabilization Techniques
	7.7 Summary
	References
	Further Reading
8. Laser Cooling and Trapping
	8.1 Introduction
	8.2 Theory of Atom–Light Interactions
		8.2.1 Incoherent Excitation: Einstein A and B Coefficients
		8.2.2 Momentum Associated with Atom–Light Interactions: Radiation Pressure
		8.2.3 Coherent Excitation
			8.2.3.1 The Light Shift
		8.2.4 The Rabi Solution
		8.2.5 The Optical Bloch Equations
	8.3 Light Forces
		8.3.1 The Dipole Force
		8.3.2 The Spontaneous Force
		8.3.3 Deceleration of an Atomic Beam
	8.4 Doppler Cooling
		8.4.1 One-Dimensional Doppler Cooling—Two Counter-Propagating Beams
		8.4.2 Equilibrium Temperature
		8.4.3 Optical Molasses in Three Dimensions
	8.5 Sub-Doppler Cooling
	8.6 Trapping of Cold Atoms
		8.6.1 The Magneto-Optical Trap
		8.6.2 Magnetic and Optical Dipole Traps
	8.7 Laser-Cooling Technology
	8.8 Summary
	References
	Further Reading
9. Precision Timekeeping: Optical Atomic Clocks
	9.1 Principles of Atomic Clocks
		9.1.1 Clock Stability
		9.1.2 Clock Accuracy
	9.2 Ultra-stable Optical Cavities and Optical Frequency Combs
		9.2.1 Ultra-stable Optical Cavities
		9.2.2 Optical Frequency Combs
	9.3 Optical Atomic Clocks
		9.3.1 Clock Interrogation Sequences
		9.3.2 Common Optical Clock Systematic Shifts
			9.3.2.1 Magnetic Fields
			9.3.2.2 Electric Fields
			9.3.2.3 Blackbody Radiation
			9.3.2.4 Doppler Shifts
			9.3.2.5 Gravitational Redshift
		9.3.3 Single-Ion Optical Clocks
			9.3.3.1 Ion Clock Operation
			9.3.3.2 Ion Clock Systematics
		9.3.4 Neutral Atom Optical Lattice Clocks
			9.3.4.1 Optical Lattice Clock Operation
			9.3.4.2 Optical Lattice Clock Systematics
	9.4 Outlook and Future Directions
		9.4.1 Next-Generation Clocks
			9.4.1.1 3 D Optical Lattice Clocks
			9.4.1.2 Cryogenic Optical Clocks
			9.4.1.3 Superradiant Optical Clocks
			9.4.1.4 Entangled Clocks
			9.4.1.5 Exotic Atomic Clocks
		9.4.2 Emerging Applications of Optical Clocks
			9.4.2.1 SI Unit Definitions, the World Clock, Navigation, and Geodesy
			9.4.2.2 Searches for Variations of Fundamental Constants, Dark Matter, and Gravitational Waves
			9.4.2.3 Many-Body Quantum Physics
	References
	Further Reading
10. Optical Atomic Clock and Laser Applications to Length and Time Metrology
	10.1 Introduction
	10.2 Outline of Optical Atomic Clocks
	10.3 Optical Clocks Based on Single Trapped Ion
		10.3.1 Ion Trapping
		10.3.2 Ion Optical Clocks Referenced to Quadrupole Transitions
		10.3.3 Ion Optical Clocks Referenced to the Transitions Other Than the Quadrupole Transitions
		10.3.4 Evaluation of Systematic Shifts
	10.4 Optical Clocks Based on Neutral Atoms
		10.4.1 Preparation of Neutral Atoms for Interrogation
		10.4.2 Spectroscopy and Laser Locking
		10.4.3 Systematic Evaluations
	10.5 Absolute Frequency Measurement and Optical Frequency Synthesis Using Femtosecond Combs
		10.5.1 Absolute Optical Frequency Measurement
		10.5.2 Optical Frequency Ratio Measurement
		10.5.3 Optical Frequency Synthesis
	10.6 Internationally Recommended Optical Frequency Standards and Optical Clocks
	References
11. Gravitation Measurements with Laser Interferometry
	11.1 Introduction
	11.2 Gravitational Wave Detection
		11.2.1 First Detection
		11.2.2 Detector Design
			11.2.2.1 Laser Source and Input Optics
			11.2.2.2 Fabry-Perot Cavities
			11.2.2.3 Interferometer Control and Gravitational Wave Signal Extraction
		11.2.3 Future Work on Earth and in Space
	11.3 Absolute Gravimetry
		11.3.1 Falling Corner Cube Gravimeters
			11.3.1.1 Laser Source
			11.3.1.2 Falling Corner Cube
			11.3.1.3 Drag-Free Chamber and Drop Mechanism
			11.3.1.4 Super-spring Inertial Reference
			11.3.1.5 Signal Acquisition and Analysis
			11.3.1.6 Current Status and Future Work
		11.3.2 Cold Atom Gravimeters
			11.3.2.1 Atomic Fountain
			11.3.2.2 Atom Interferometry
			11.3.2.3 Raman Transitions and Atom Interferometery
			11.3.2.4 Inertial Reference
			11.3.2.5 Current Status of Cold-Atom Gravimeters
			11.3.2.6 New Methods
	11.4 Determination of the Newtonian Constant of Gravitation
		11.4.1 Free-Falling Corner Cube Determination
		11.4.2 Atom Interferometer Determinations
		11.4.3 Suspended Fabry-Perot Cavity Determination
	References
12. Satellite Laser Ranging
	12.1 Introduction
	12.2 Working Principle
		12.2.1 General Description
		12.2.2 Components
			12.2.2.1 Ground Segment
			12.2.2.2 Space Segment
	12.3 Operations
		12.3.1 Signal Strength
			12.3.1.1 Track Detection
			12.3.1.2 Data Screening
		12.3.2 Ranging Policy
		12.3.3 Calibration
		12.3.4 Safety
		12.3.5 Global Network
	12.4 Analysis
		12.4.1 Centre of Mass Corrections
		12.4.2 Accuracy and Quality Control
	12.5 Applications
		12.5.1 Terrestrial Reference Frame
		12.5.2 Support of Scientific Missions
		12.5.3 Tracking of GNSS Constellations
		12.5.4 Space Debris
		12.5.5 Time Transfer
		12.5.6 Lunar Laser Ranging
	12.6 Concluding Remarks and Future Trends
	References
13. Lasers in Medical: Section Introduction
14. Light–Tissue Interactions
	14.1 Introduction
	14.2 Fundamental Interactions
		14.2.1 Absorption
		14.2.2 Luminescence
		14.2.3 Elastic Scattering
		14.2.4 Scattering by a Dielectric Particle
		14.2.5 Scattering by Many Particles
		14.2.6 Inelastic Scattering
		14.2.7 Miscellaneous
	14.3 Optical Properties of Tissue and Their Measurement
		14.3.1 Absorption Coefficient
		14.3.2 Scattering Coefficient
		14.3.3 Scattering Phase Function
		14.3.4 Measurement of Optical Properties Ex Vivo
		14.3.5 Measurement of Optical Properties In Vivo
	14.4 Physical Models of Light Propagation in Tissue
		14.4.1 The Radiative Transport Equation
		14.4.2 Numerical Solution of the RTE
		14.4.3 Monte Carlo Simulation
		14.4.4 The Diffusion Approximation
		14.4.5 Fluence Rate Distributions in Tissue
	14.5 Therapeutic Laser–Tissue Interactions
		14.5.1 Introduction
		14.5.2 Photochemical Effects
		14.5.3 Photothermal Effects
			14.5.3.1 Laser Heating
			14.5.3.2 Thermal Diffusion
			14.5.3.3 Thermal Damage
		14.5.4 Photomechanical Effects
			14.5.4.1 Thermoelastic Expansion
			14.5.4.2 Spallation and Cavitation
			14.5.4.3 Vaporization
			14.5.4.4 Plasma Formation
	14.6 Summary
	References
15. Ophthalmic Laser Therapy and Surgery
	15.1 Introduction
		15.1.1 Early History
		15.1.2 Optical Properties of the Eye
	15.2 Photothermal Therapy
		15.2.1 Photothermal Interactions
		15.2.2 Quantification of Thermal Damage
		15.2.3 Photocoagulation
			15.2.3.1 Retinal Plasticity Following Photocoagulation
			15.2.3.2 Optimization of Pulse Duration for Photocoagulation
			15.2.3.3 Pattern-Scanning Retinal Photocoagulation
			15.2.3.4 Non-damaging Laser Therapy of the Macula
			15.2.3.5 Real-Time Monitoring of Tissue Temperature
			15.2.3.6 Laser Trabeculoplasty
	15.3 Tissue-Selective Therapy Using Photochemical Interactions
	15.4 Photomechanical Interactions
		15.4.1 Selective RPE Therapy
		15.4.2 Selective Laser Trabeculoplasty
		15.4.3 Corneal Ablation for Refractive Surgery
	15.5 Transparent Tissue Surgery with Ultrashort-Pulse Lasers
		15.5.1 Refractive Surgery
		15.5.2 Vitreoretinal Surgery
		15.5.3 Cataract Surgery
	15.6 Summary and Future Directions
	Disclosure Statement
	References
16. Therapeutic Application: Refractive Surgery
	16.1 Introduction
	16.2 Excimer Laser-Based Procedures
	16.3 Excimer Laser-Based Procedures Complications
	16.4 FSL-Based Procedures
	16.5 ReLEx Procedures
	16.6 Newer Application of Small-Incision Lenticule Extraction
	References
17. Photodynamic Therapy
	17.1 Introduction
	17.2 Light Sources
		17.2.1 Lasers
		17.2.2 Non-laser Sources
	17.3 Light Delivery Systems
	17.4 Optical Monitoring and Dosimetry
	17.5 Alternative Photosensitizer Activation Schemes
		17.5.1 Two-photon Activation
		17.5.2 Up-converting Nanoparticles
		17.5.3 Bioluminescence Activation
		17.5.4 Ultrasound Activation
		17.5.5 Ionizing Radiation Activation
	17.6 PDT for Cancer Treatment
	17.7 Other Applications of PDT
	17.8 Conclusions
	Bibliography
18. Therapeutic Applications: Thermal Treatment of Tumours
	18.1 Introduction
	18.2 Laser Therapy with Flexible Endoscopes
		18.2.1 Cancers of the Gastrointestinal Tract
		18.2.2 Cancer of the Lungs
		18.2.3 Urology
	18.3 Interstitial Laser Photocoagulation
	18.4 Conclusion
	References
19. Therapeutic Applications: Dermatology—Selective Photothermolysis
	19.1 Introduction
		19.1.1 Photothermal Interactions
		19.1.2 Selective Photothermolysis
	19.2 Laser Treatment of Cutaneous Vascular Lesions
		19.2.1 Principles of Selective Photothermolysis and the Treatment of PWSs
	19.3 Laser Treatment of Pigmented Lesions and Tattoos
	19.4 Laser Treatment of Hair by Selective Photothermolysis
	19.5 Carbon Dioxide and Erbium:YAG Lasers in Dermatology
		19.5.1 Erbium:YAG Laser in Dermatology
	References
20. Therapeutic Applications: Lasers in Vascular Surgery
	20.1 Atheroma and Angioplasty-Like Injury
	20.2 Laser Angioplasty
	20.3 Reported and Ongoing Studies on Excimer Laser Angioplasty
		20.3.1 Coronary Arteries
		20.3.2 Peripheral (Femoral) Arteries
	20.4 PDT in the Arteries
		20.4.1 PDT of Injured and Diseased Arteries
		20.4.2 Light Delivery
		20.4.3 Clinical Data
	20.5 Conclusions
	References
21. Therapeutic Applications: Free-Electron Laser
	21.1 Introduction
	21.2 Laser Ablation
		21.2.1 Ablation with the FEL
	21.3 Towards Clinical Application of the FEL
		21.3.1 Beam Transport and Alignment
		21.3.2 Surgical Beam Delivery
	21.4 Clinical Experience
		21.4.1 Neurosurgery
		21.4.2 Clinical Experience: Ophthalmology
	21.5 Conclusions
	References
22. Medical Diagnostics
	22.1 Introduction
	22.2 In Vivo Methods and Applications
		22.2.1 White-Light (Reflectance) Imaging
		22.2.2 Diffuse Optical Spectroscopy and Spectral Imaging
		22.2.3 Elastic Scattering Spectroscopy
		22.2.4 Optical Coherence Tomography
		22.2.5 Confocal Imaging
		22.2.6 Fluorescence Spectroscopy and Imaging
		22.2.7 Raman Spectroscopy and Imaging
			22.2.7.1 Photoacoustic Imaging
		22.2.9 Other Methods
		22.2.10 Optical Imaging in Pathology
	22.3 Comparison of Techniques and General Future Trends
	Bibliography
23. Broad Bandwidth Light Sources in Optical Coherence Tomography (OCT)
	23.1 Introduction to OCT
		23.1.1 Time Domain OCT
		23.1.2 Fourier Domain OCT
	23.2 Broadband Sources for OCT
		23.2.1 Femtosecond Lasers
		23.2.2 Swept Source Lasers
		23.2.3 Supercontinuum Sources
		23.2.4 Superluminescent Diodes
	23.3 Source Parameters and Their Indications for OCT Performance
		23.3.1 Spectrum (Central Wavelength and Bandwidth)
		23.3.2 Source Noise
		23.3.3 Instantaneous Linewidth of a Swept Source
		23.3.4 Repetition/Sweep Rate of Broadband Sources
	23.4 Conclusions
	References
24. Laser Applications in Biology and Biotechnology
	24.1 Introduction
	24.2 Light Interaction with Matter
		24.2.1 Absorption of Light
		24.2.2 Emission of Light
		24.2.3 Scattering of Light
		24.2.4 Quantum Confinement—Quantum Dots
	24.3 Laser Probing of Biological Samples
		24.3.1 Endogenous Molecular Probes
			24.3.1.1 Endogenous Absorbers
			24.3.1.2 Endogenous Fluorophores
		24.3.2 Exogenous Probes
			24.3.2.1 Small Organic Fluorescent Probes
			24.3.2.2 Fluorescent Protein-Based Probes
			24.3.2.3 Quantum Dots
			24.3.2.4 Raman Probes—Surface-Enhanced Raman Scattering
		24.3.3 Optical Spectroscopy
			24.3.3.1 Steady-State Measurements
			24.3.3.2 Time-Resolved Measurements
			24.3.3.3 Applications to Tissue Diagnostics
		24.3.4 Spectral Imaging
	24.4 Laser-Based Imaging: Applications Classified Using the Properties of Light
		24.4.1 Applications Based on Linear Optical Responses
			24.4.1.1 Laser Scanning Confocal Fluorescence Microscopy (LSCFM)
			24.4.1.2 Laser Microscopy Beyond the Diffraction Limit
		24.4.2 Applications Based on Non-linear Optical Responses
			24.4.2.1 Multi-photon Laser Scanning Fluorescence Microscopy
			24.4.2.2 Imaging Techniques Exploiting Second Harmonic Generation (SHG)
			24.4.2.3 Imaging Techniques Employing Coherent Anti-stokes Raman Scattering (CARS)
			24.4.2.4 Surface-Enhanced Raman Scattering
		24.4.3 Spectral-Based Applications—Imaging Beyond the Visible Region
			24.4.3.1 Imaging with Soft X-rays in the ‘Water-Window’ Region
			24.4.3.2 Imaging with Lasers Operating in the ‘Water-Window’ Region
	24.5 Laser-Based Imaging: Applications to Different Levels of Biological Organization
		24.5.1 Single-Molecule Detection
		24.5.2 Imaging at Sub-cellular Level
		24.5.3 Imaging of Organelles and Bacteria
		24.5.4 Imaging at Cellular Level
		24.5.5 Imaging in Tissue
	24.6 Lasers for Micromanipulation of Biological Samples
		24.6.1 Opto-Mechanical Manipulation of Biological Samples
			24.6.1.1 Optical Tweezers
			24.6.1.2 Perforation (Optoporation)
			24.6.1.3 Nanosurgery (Laser Scalpels)
			24.6.1.4 Tissue Welding and Soldering
		24.6.2 Physico-Chemical Manipulation of Biological Samples
			24.6.2.1 Pump-Probe Technique
			24.6.2.2 Laser-Activated Processes
		24.6.3 Fluorescence Correlation Spectroscopy
		24.6.4 Flow Cytometry
	24.7 Emerging Applications of Lasers in Biotechnology
		24.7.1 DNA Micro-arrays and Genomics
		24.7.2 Protein Micro-arrays and Proteomics
		24.7.3 Bio-Cavity Lasers
	References
25. Biomedical Laser Safety
	25.1 Introduction
	25.2 Laser Accidents
		25.2.1 Case Studies
	25.3 Classes of Lasers in Medical Use
		25.3.1 Class 1
		25.3.2 Class 1C
		25.3.3 Class 1M
		25.3.4 Class 2
		25.3.5 Class 2M
		25.3.6 Class 3R
		25.3.7 Class 3B
		25.3.8 Class 4
	25.4 Intense Pulsed Light Sources
	25.5 Principles of Quality Assurance
	25.6 Laser Standards and Guidelines
		25.6.1 Electrical and Mechanical Construction
		25.6.2 Optical Radiation Safety Documents
		25.6.3 Optical Beam Specification
		25.6.4 General Optical Safety Guidance
	25.7 Laser Safety Management
		25.7.1 Optical Radiation Safety Policy
		25.7.2 Laser Protection Adviser
		25.7.3 Laser Protection Supervisor
		25.7.4 Local Rules
		25.7.5 Laser Controlled Area
		25.7.6 Authorized Users
		25.7.7 Training
		25.7.8 Medical Examination
		25.7.9 Incident Reports
		25.7.10 Equipment
		25.7.11 Equipment Modification
		25.7.12 Legislative Health and Safety Requirements
		25.7.13 Conclusion
	25.8 Precautions
		25.8.1 Hazards to the Eye
		25.8.2 Hazards to the Skin
		25.8.3 Equipment Features
		25.8.4 Room Layout
		25.8.5 Protective Eyewear
		25.8.6 Risk Assessment
	25.9 Reflections
	25.10 Fires
	25.11 Hazards to Patients
		25.11.1 Risk to Eyes
		25.11.2 Risk to Skin
		25.11.3 Misdirected Beam
		25.11.4 Endotracheal Tube Ignition
		25.11.5 Carbonization
	25.12 Incidental Hazards
		25.12.1 Laser Plume
		25.12.2 Electrical Danger
		25.12.3 Carcinogenic Dyes
		25.12.4 Fire
	25.13 Conclusion
	References
	Further Reading
26. Laser in Communications: Section Introduction
27. Fibre-to-the-Chip: Development of Vertical Cavity Surface-Emitting Laser Arrays Designed for Integration with VLSI Circuits
	27.1 Introduction and Background
	27.2 VCSEL: The P[sup(2)]I[sup(2)] VCSEL Design
	27.3 First Implementation: The I[sup(2)]-VCSEL
	27.4 Design Modifications for High-Speed P[sup(2)]I[sup(2)]-VCSELs
	27.5 Results from the First High-Speed P[sup(2)]I[sup(2)]-VCSELs377
	27.6 Conclusions
	Acknowledgments
	References
28. Advances in Laser Satellite Communications
	28.1 Introduction
		28.1.1 Lasercom Benefits
		28.1.2 Lasercom Challenges
		28.1.3 Technology Maturity
		28.1.4 Link Budget
	28.2 Technology and Design Drivers
		28.2.1 Laser Beam Spatial Acquisition, Tracking, Pointing and Stabilization
		28.2.2 Rugged Opto-Mechanical and Thermo-Mechanical Optics
		28.2.3 Signal Detection
		28.2.4 Modulation and Coding
		28.2.5 Flight Laser Transmitter
		28.2.6 The Atmospheric Channel
			28.2.6.1 Mitigating Effects of Turbulence/Scintillation
	28.3 Ground Station
		28.3.1 Ground Receive Telescope
		28.3.2 Ground Uplink Transmitter
		28.3.3 Ground PAT
	28.4 Applications
	References
29. Passive Silicon Photonic Integrated Components and Circuits for Optical Communications
	29.1 Introduction
	29.2 Silicon Nanophotonic Waveguides
	29.3 Silicon Photonic Devices for On-Chip Polarization-Handling
		29.3.1 Silicon PBSs
		29.3.2 Silicon PRs
	29.4 Multi-mode Silicon Photonics
		29.4.1 On-Chip Mode (De)Multiplexers
		29.4.2 Sharp Multi-mode Waveguide Bends
	29.5 Wavelength-Selective Silicon Photonic Devices
		29.5.1 AWG-Based Optical Filters
		29.5.2 MRR-Based Optical Filters
			29.5.2.1 MRR-Based Optical Filters with Large FSRs
			29.5.2.2 MRR-Based Optical Filters with Box-Like Responses
			29.5.2.3 Polarization-Selective MRR Optical Filters
		29.5.3 Grating-Based Optical Filters
	29.6 Reconfigurable Silicon Photonic Devices and Circuits
		29.6.1 Optical Switches
		29.6.2 ROADMs
	29.7 Conclusion and Future Trends
	References
30. Fibre-Optic Transmission Systems from Chip-to-Chip Interconnects to Trans-Oceanic Cables
	30.1 The Role of Fibre Optics in Communications
	30.2 Modulation and Multiplexing: Theoretical and Practical Limits
		30.2.1 Digital Modulation and Multiplexing in a Nutshell
		30.2.2 Practical Aspects of Modulation and Multiplexing in Optical Communications
	30.3 Fibre-Optic Communication Systems from Short-Reach to Ultra-Long-Haul
		30.3.1 Short-Reach Systems (≤ 10 km )
		30.3.2 Mobile Front-Haul and PONs
		30.3.3 Datacentre Interconnects (≤ 100 km)
		30.3.4 Metro and Long-Haul Networks (100 km ~ 5000 km)
		30.3.5 Sub-marine Transmission ( ≥ 5000 km)
	References
31. Visible Light Communications and LiFi
	31.1 Introductions
	31.2 Communication Front-End Characterization
		31.2.1 Transmitters
			31.2.1.1 White-Coloured LEDs
			31.2.1.2 White-Coloured LDs
			31.2.1.3 Micro-Sized LEDs
			31.2.1.4 Resonant Cavity LEDs
			31.2.1.5 Organic LEDs
		31.2.2 Receivers
			31.2.2.1 PIN-PDs and APDs
			31.2.2.2 Single-Photon APDs
			31.2.2.3 PV Solar Cells
	31.3 Indoor VLC Channel Characterizations
		31.3.1 Line-of-Sight Channel and Non-line-of-Sight Channel
		31.3.2 Deterministic Method
		31.3.3 Monte Carlo Method
		31.3.4 Frequency Domain Calculation
		31.3.5 Simplified Sphere Model
		31.3.6 Efficient Analytical Method
		31.3.7 Comparison of NLoS Channel Calculation Methods
	31.4 Digital Modulation Techniques
		31.4.1 Single-Carrier Modulation Techniques
		31.4.2 OFDM-Based MCM
			31.4.2.1 DCO-OFDM
			31.4.2.2 Unipolar OFDM Techniques
			31.4.2.3 Hybrid OFDM Techniques
		31.4.3 Colour Modulation Techniques
	31.5 Multiple-Input Multiple-Output Techniques in VLC and LiFi
		31.5.1 Spatial Multiplexing
		31.5.2 Repetition Coding
		31.5.3 Spatial Modulation
		31.5.4 Electrical-to-Optical Conversion Based on Multiple Light Sources
		31.5.5 MIMO Optical Source and Detector Deployment in VLC and LiFi
		31.5.6 Adaptation of MIMO techniques
	31.6 Co-channel Interference and Interference Mitigation Techniques in Multi-Cell LiFi Networks
		31.6.1 Access Point Layout and SINR Characterizations
		31.6.2 Interference Mitigation Techniques
	31.7 Conclusion
	References
32. Optical Data Storage
	32.1 von Neumann Architecture: CMOS Technologies
	32.2 von Neumann Bottleneck
	32.3 Non-von Neumann Architecture: Memcomputing
	32.4 Non-volatile Photonic Memory
	32.5 Photonic Memelements for Non-von Neumann Architecture
	32.6 Other Method of Optical Memory
	32.7 Associative Optical Memory for Pattern Recognition
	References
Index