| 1. Introduction 1 |
| 1.1 Outline of Semiconductor Laser Theory 1 |
| 1.2 Semiconductor Lasers in Opto-electronics 3 |
| 1.3 Necessary Technology for Semiconductor Lasers 4 |
| 1.4 Brief History of Semiconductor Lasers 5 |
| 1.5 Typical Semiconductor Lasers 7 |
| 2. Materials for Semiconductor Lasers 8 |
| 2.1 III-V Compound Semiconductors 8 |
| 2.1.1 Band Structure of III-V Semiconductors 8 |
| 2.1.2 Other Characteristics of III-V Compound Semiconductors 13 |
| 2.2 Crystals for Visible to Near-Infrared-Wavelength Emission Semiconductor Lasers 15 |
| 2.2.1 Importance of Visible to Near-Infrared-Wavelenth Laser Emission 15 |
| 2.2.2 Crystal Materials for the Near-Infrared Region 15 |
| 2.2.3 Crystal Materials for Visible Laser Emission 17 |
| 2.3 Crystals for Semiconductor Lasers with 1-μm and Longer Emission Wavelengths 18 |
| 2.3.1 Importance of the 1-μm Emission Wavelength 18 |
| 2.3.2 Crystal Materials for the 1-μm Emission Wavelength 20 |
| 2.3.3 Longer-Wavelength Materials 21 |
| 3. Basic Design of Semiconductor Lasers 22 |
| 3.1 Double Heterostructures and Their Design 22 |
| 3.1.1 Double Heterostructures 22 |
| 3.1.2 Design of Double-Heterostructure Lasers 23 |
| 3.1.3 Energy-Band Diagram of DH Lasers 24 |
| 3.1.4 Optical Properties of DH Lasers 32 |
| a) Step-Index Planar Waveguide 32 |
| b) TE Modes 34 |
| c) TM Modes 37 |
| d) Mode-Confinement Factor 38 |
| 3.1.5 Threshold Current of DH Lasers 40 |
| 4. Epitaxy of III-V Compound Semiconductors 43 |
| 4.1 III-V Substrates for Semiconductor Lasers 43 |
| 4.1.1 Necessity of Substrates 43 |
| 4.1.2 Substrate Quality Requirements 43 |
| 4.2 Bulk Growth Techniques 45 |
| 4.3 Heteroepitaxial Techniques 45 |
| 4.3.1 Liquid-Phase Epitaxy 45 |
| 4.3.2 Vapor-Phase Epitaxy 47 |
| 4.3.3 Metalo-Organic Chemical-Vapor Deposition 47 |
| 4.3.4 Molecular Beam Epitaxy 48 |
| 4.3.5 Chemical Beam Epitaxy 49 |
| 5. Liquid Phase Epitaxy and Growth Technology 51 |
| 5.1 Outline of an LPE System 51 |
| 5.2 Reactors 52 |
| 5.2.1 Horizontal Reactor 52 |
| 5.2.2 Vertical Reactor 56 |
| 5.3 Loading Sub-System 57 |
| 5.4 Pump and Exhaust Sub-System 58 |
| 5.5 Gas-Flow Sub-System 59 |
| 5.6 Heating Sub-System 60 |
| 5.7 Maintenance 60 |
| 5.7.1 Maintenance of a Graphite Boat 60 |
| 5.7.2 Baking of the Reactor 60 |
| 5.8 Liquid-Phase Epitaxy 61 |
| 5.9 LPE Process 63 |
| 5.9.1 GaA1As/GaAs System 63 |
| a) Determination of the Source-Material Quantity 63 |
| b) LPE Procedure 67 |
| 5.9.2 GaInAsP/InP System 69 |
| 5.9.3 Other Materials 77 |
| a) Visible-Light Semiconductor Lasers 80 |
| b) Longer-Wavelength (λ＞2μm) Semiconductor Lasers 81 |
| 6. Vapor Phase and Beam Epitaxies 82 |
| 6.1 Metal-Organic Chemical Vapor Deposition (MOCVD) 82 |
| 6.1.1 MOCVD System 82 |
| 6.1.2 Example of MOCVD Growth 84 |
| a) A Double-Heterostructure Wafer 84 |
| b) Semiconductor Multilayer Reflector 85 |
| 6.1.3 Characterization 87 |
| a) Evaluation of the Nominal Threshold-Current Density 87 |
| b) Reflectivity of a Multilayer Bragg Reflector 88 |
| 6.2 Molecular-Beam and Chemical-Beam Epitaxy 89 |
| 6.2.1 Background 89 |
| 6.2.2 Chemical Beam Epitaxial System 91 |
| 6.2.3 Preparation for Growth 92 |
| 6.2.4 GaAs and InP Growth 93 |
| 6.2.5 GaxIn1-xAsyP1-y Growth 96 |
| 6.2.6 Doping-Level Control 98 |
| 6.2.7 Summary of CBE 99 |
| 7. Characterization of Laser Materials 101 |
| 7.1 Evaluation of Laser Wafers 101 |
| 7.2 Measurement of Lattice Mismatch 103 |
| 7.3 Measurement of the Impurity Concentration 105 |
| 7.3.1 Four-Point Probe Method 105 |
| 7.3.2 Schottky Method 107 |
| 7.3.3 Hall Measurement 108 |
| 7.4 Photoluminescence 110 |
| 7.5 Measurement of the Refractive Index 111 |
| 7.6 Misfit Dislocation 111 |
| 8. Semiconductor-Laser Devices-Fabrication and Characteristics 112 |
| 8.1 Fabrication of Fundamental Laser Devices 112 |
| 8.1.1 Broad Contact Lasers 112 |
| 8.1.2 Stripe-Geometry Lasers 113 |
| 8.2 Current Injection and Contacts 114 |
| 8.2.1 Current/Voltage Characteristics 114 |
| 8.2.2 Current Injection 116 |
| 8.3 Evaluation of the Threshold-Current Density 119 |
| 8.4 Gain Bandwidth and Oscillation Spectra 119 |
| 8.5 Output and Efficiency of Semiconductor Lasers 121 |
| 8.6 Near-Field Pattern and Far-Field Pattern 122 |
| 8.7 Temperature Characteristics 122 |
| 8.8. Reliability 123 |
| 9. Mode-Control Techniques in Semiconductor Lasers 124 |
| 9.1 Transverse-Mode Characteristics and the Single-Mode Condition 124 |
| 9.1.1 Necessity of Transverse-Mode Stabilization 124 |
| 9.1.2 Equivalent Refractive-Index Method 126 |
| 9.1.3 Eigenvalue Equation of a Guided Mode 127 |
| 9.2 Longitudinal-Mode Control 129 |
| 9.3 Burying Epitaxy on Mesas and V-Grooves 133 |
| 9.3.1 Structures on Index-Guided Lasers 133 |
| 9.3.2 Fabrication of Transverse-Mode-Controlled Structures 134 |
| 9.4 Mass-Transport Technique 136 |
| 9.5 Selective Meltback Technique 137 |
| 9.5.1 Selective Meltback Characteristics 137 |
| 9.5.2 Application to an Inner-Stripe Structure 138 |
| 9.5.3 Application to BH Stripe-Lasers 140 |
| 9.6 Overgrowth on Gratings 141 |
| 9.7 Growth of Quantum Wells 141 |
| 9.8 Growth of Multilayer Bragg Mirrors 145 |
| 10. Surface-Emitting Lasers 147 |
| 10.1 The Concept of Surface-Emitting Lasers 147 |
| 10.2 Structure and Characteristics 148 |
| 10.2.1 GaInAsP/InP Surface-Emitting Lasers 148 |
| 10.2.2 GaA1As/GaAs SE Lasers 149 |
| 10.3 Semiconductor Multi-Layer Structure 150 |
| 10.4 Two-Dimensional Arrays 151 |
| 10.5 Ultralow-Threshold Devices 153 |
| 10.6 Future Prospects 154 |
| References 155 |
| Subject Index 167 |
| 1. Introduction 1 |
| 1.1 Outline of Semiconductor Laser Theory 1 |
| 1.2 Semiconductor Lasers in Opto-electronics 3 |
図書
