Chapter 1. The Basic Concept of Lasers |
1.1. What Is a Laser? 1 |
1.2. History of Lasers 4 |
1.2.1. Development of Masers 4 |
1.2.2. Development of Lasers 5 |
1.3. Characteristics of Laser Beams 6 |
1.4. Field of Optoelectronics 9 |
Problems 10 |
References 11 |
Chapter 2. Laser Applications |
2.1. Laser Characteristics and Application Areas 13 |
2.2. Optical Communications 16 |
2.2.1. Optical Communication Systems 16 |
2.2.2. Semiconductor Lasers for Optical Fiber Communication 18 |
2.2.3. Lasers as Light Sources in Communication Measurement 19 |
2.2.4. Optical Amplifiers 20 |
2.3. Laser Disks 21 |
2.4. Lightwave Sensing 23 |
2.4.1. Light Output 23 |
2.4.2. Radiation Angle of Light Beam 24 |
2.4.3. Instability of Laser Operation Caused by Optical Feedback 25 |
2.4.4. Increase of Intensity Noise Caused by Mode Hopping 25 |
2.4.5. Variation of Power Related to Temperature Change 26 |
2.4.6. Variation of Wavelength Related to Temperature Change 26 |
2.4.7. Reproducibility of Wavelenght 27 |
2.4.8. Linewidth 27 |
2.4.9. Resistivity against Electrical Surge and Lifetime 28 |
2.5. Electro-Optic Equipment 28 |
2.6. Medical Applications 29 |
2.7. Energy Development 29 |
2.8. Laser Display 30 |
Problems 30 |
References 31 |
Chapter 3. Gas and Liquid Lasers |
3.1. Gas Lasers 33 |
3.1.1. Helium-Neon Laser 33 |
3.1.2. CO2 Laser 35 |
3.1.3. Ion Lasers 36 |
3.1.4. Helium-Cadmium Laser 37 |
3.1.5. Nitrogen Laser 37 |
3.2. Excimer Lasers 38 |
3.3. Liquid Lasers 39 |
3.4. Other Lasers 40 |
Problems 40 |
References 41 |
Chapter 4. Solid-State Lasers |
4.1. Ruby Lasers 43 |
4.2. YAG Lasers 44 |
4.3. Glass Lasers 46 |
4.4. Optical Fiber Laser Amplifiers 46 |
4.5. Other Solid-State Lasers 47 |
Problems 48 |
References 48 |
Chapter 5. Semiconductor Lasers-Materials and Devices |
5.1. Outline of Semiconductor Lasers 49 |
5.1.1. Development of Semiconductor Lasers 49 |
5.1.2. Fundamentals of Semiconductor Lasers 51 |
5.2. Materials for Semiconductor Lasers 52 |
5.2.1. Crystals for 1-μm-Band Semiconductor Lasers 52 |
5.2.2. Crystals for Visible to Near-Infrared Semiconductor Lasers 56 |
5.3. Basic Concept of Semiconductor Lasers 58 |
5.3.1. Oscillation Conditions 58 |
5.3.2. Gain Width and Oscillation Spectra 60 |
5.3.3. Transverse Mode Characteristics 62 |
5.3.4. Threshold and Efficiency 64 |
5.3.5. Near-and Far-Field Patterns 65 |
5.3.6. Temperature Characteristics 65 |
Problems 66 |
References 67 |
Chapter 6. Light Beams |
6.1. Equations Expressing an Electromagnetic Field of Light 71 |
6.1.1. Passive Case 73 |
6.1.2. Active Case 74 |
6.2. Normal Modes 75 |
6.3. Normal Modes in Distributed Index (DI) Waveguides 77 |
6.4. Expansion Methods for Normal Modes 82 |
6.5. Gaussin Beams in Free Space 86 |
6.6. Transformation Matrix of Waveform and Ray Transfer Matrix 89 |
6.6.1. Transformation Matrix of Waveforms 89 |
6.6.2. Ray Transfer Matrix 93 |
6.7. Representation of Waveform Coefficient Transformation by the Smith Chart 95 |
6.8. Appendix 1: Matrix of a DI Waveguide 96 |
6.9. Appendix 2: Transfer Matrices in Free Space 100 |
Problems 101 |
References 101 |
Chapter 7. Optical Waveguides for Laser Technology |
7.1. Normal Modes in a Planar Dielectric Waveguide 103 |
7.2. Modes of a Three-Dimensional Waveguide 113 |
7.3. Confinement Factor 114 |
7.4. Radiation from the Edge of a Waveguide 115 |
Problems 117 |
References 118 |
Chapter 8. Laser Resonators and Resonant Modes |
8.1. Introduction 119 |
8.2. Fabry-Perot Waveguide-Type Resonators 121 |
8.3. Open Fabry-Perot Resonators with Concave Mirrors 125 |
8.3.1. Spotsize 125 |
8.3.2. Stability of Resonators 126 |
8.3.3. Mode and Diffraction Loss in Fabry-Perot Resonators 129 |
8.3.4. Resonance Frequency 137 |
8.4. Distributed Feedback/Reflector Resonators 139 |
8.4.1. Resonance Frequencies 139 |
8.4.2. Diffracted Waves 140 |
8.4.3. Stop Bands 142 |
8.4.4. Distributed Bragg Reflector-Type Resonators 146 |
8.4.5. λB/4 Phase Shift 147 |
8.5. Resonator Loss and Resonance Characteristics 148 |
8.5.1. Decay Time and Q-Value 148 |
8.5.2. Resonance Characteristics and Transfer Function 149 |
8.6. Summary 150 |
Problems 150 |
References 151 |
Chapter 9. Laser Equations |
9.1. Density Matrix and Equations of Motions 153 |
9.1.1. Density Matrix 153 |
9.1.2. Density Operator and Density Matrix in the Pure State 155 |
9.1.3. Density Operator in a Continuous Eigenstate 156 |
9.2. Dipole Transition 158 |
9.2.1. Diagonal Elements of the Density Matrix 158 |
9.2.2. Nondiagonal Elements of the Density Matrix 160 |
Problems 163 |
References 163 |
Chapter 10. Rate Equations |
10.1. Homogeneous Gain 165 |
10.2. Rate Equations 167 |
10.3. Laser Gain 170 |
10.3.1. Laser Gain 171 |
10.3.2. Gain of Semiconductor Lasers 172 |
10.3.3. Quantum Well Lasers 174 |
10.4. Oscillation Conditions 177 |
Problems 180 |
References 181 |
Chapter 11. Laser Gain and Saturation |
11.1. Inhomogeneous Broadening 183 |
11.2. Hole Burning 184 |
11.3. Saturation of Light Output 189 |
11.4. Gain and Saturation in Semiconductor Lasers 194 |
Problems 204 |
References 205 |
Chapter 12. Modulation and Light Pulse Generation |
12.1. Delay in Laser Oscillation 207 |
12.2. Relaxation Oscillation 208 |
12.3. Q-Switching 210 |
12.4. Mode Locking 212 |
12.5. Direct Modulation 214 |
Problems 216 |
References 217 |
Chapter 13. Laser Noise |
13.1. Intensity Noise 219 |
13.1.1. Measure of Intensity Noise 219 |
13.1.2. Quantum Noise 220 |
13.1.3. Enhancement of Intensity Noise by Various Factors 223 |
13.1.4. Stabilization of Laser Output 224 |
13.2. Frequency Noise 224 |
13.2.1. Expression for Frequency Noise 224 |
13.2.2. Quantum Noise 224 |
13.2.3. Enhancement of Frequency Noise by Various Factors 227 |
13.2.4. Measuring Linewidth 227 |
13.3. Control of Linewidth 228 |
13.3.1. Optical Methods 228 |
13.3.2. An Electric Method 229 |
13.4. Laser Frequency Stabilization 229 |
13.4.1. Allan Variance 229 |
13.4.2. Stabilization at the Center of Laser Gain 230 |
13.4.3. Stabilization with an External Frequency Standard 230 |
Problems 231 |
References 231 |
Chapter 14. Advanced Technology for Semiconductor Laser Fabrication and Integration |
14.1. Methods of Semiconductor Crystal Growth 233 |
14.1.1. Outline of Crystal Growth Method 233 |
14.1.2. Liquid-Phase Epitaxy 234 |
14.1.3. Vapor-Phase Epitaxy 238 |
14.1.4. Metal-Organic Chemical Vapor Deposition 239 |
14.1.5. Molecular Beam Epitaxy 240 |
14.1.6. Chemical Beam Epitaxy 241 |
14.2. Laser Devices and Fabrication Processes 241 |
14.2.1. Energy Band Structures in Heterojunction Devices 241 |
14.2.2. Doping 244 |
14.2.3. Fabrication Methods of Wafers for Lasers 245 |
14.3. Evaluation of Wafers 247 |
14.3.1. Observation of Surface Morphology 248 |
14.3.2. Observation of Cross Sections 248 |
14.3.3. Determining Composition 248 |
14.3.4. Determining the Band Gap, Eg 248 |
14.3.5. Measuring Lattice Matching 249 |
14.3.6. Photoluminescence 249 |
14.3.7. Measurement of Refractive Index 250 |
14.3.8. Misfit Density 251 |
14.4. Fabrication of Fundamental Laser Devices and Characterization Methods 251 |
14.4.1. Fabrication Method of Fundamental Laser Devices 251 |
14.4.2. Stripe-Geometry Lasers 253 |
14.5. Longitudinal Mode Control 254 |
14.6. Modulation and Noise 257 |
14.6.1. Modulation and Bandwidth of a Semiconductor Laser 257 |
14.6.2. Noise 258 |
14.6.3. Frequency Stability 259 |
14.7. Prospects of Semiconductor Lasers 260 |
14.7.1. Laser Arrays 260 |
14.7.2. Integration 261 |
14.7.3. Prospects of Optical Subsystems 263 |
Problems 264 |
References 264 |
Chapter 15. Surface-Emitting Lasers |
15.1. Advantages of Surface-Emitting Lasers 267 |
15.2. History of Vertical Cavity Surface-Emitting Lasers 270 |
15.3. Vertical Cavity Surface-Emitting Lasers (VCSEL) 271 |
15.3.1. GaInAsP/InP Surface-Emitting Lasers 271 |
15.3.2. GaA1As/GaAs Surface-Emitting Lasers 273 |
15.3.3. GaInAs/GaAs Surface-Emitting Lasers 275 |
15.4. Ultimate Threshold and Spontaneous Emission Control 275 |
15.4.1. Ultimate Threshold 275 |
15.4.2. Spontaneous Emission Control 275 |
15.4.3. Photon Recycling 276 |
15.5. Two Dimensional Arrays of Surface-Emitting Lasers 277 |
15.6. Applied Subsystems 278 |
15.7. Prospects 280 |
References 280 |
Index 283 |
Chapter 1. The Basic Concept of Lasers |
1.1. What Is a Laser? 1 |
1.2. History of Lasers 4 |