High-Power Diode Lasers: Fundamentals, Technology, Applications: With Contributions by Numerous Experts

Topics in Applied Physics 78......Page 1
High-Power Diode Lasers......Page 3
Preface......Page 5
Contents......Page 9
Emission and Absorption in Semiconductors......Page 15
Basic Elements of Semiconductor-Diode Lasers......Page 22
Optical Gain and Threshold Condition......Page 24
Edge- and Surface-Emitting Lasers......Page 27
Lateral Confinement......Page 29
Quantum-Well Structures......Page 32
Fabrication Technology......Page 34
Effective Refractive Index......Page 38
Normalized Propagation Diagrams......Page 40
Optical Near- and Far-Field Patterns......Page 42
Fabry-Perot Resonator......Page 45
Diode-Laser Spectrum......Page 47
Mirror Coatings......Page 48
Rate Equations for Electronic Carriers and Photons......Page 51
Electrical and Optical Characteristics of Power Diode Lasers......Page 55
Design Considerations for High-Power Operation......Page 60
References......Page 66
Dynamics of High-Power Diode Lasers......Page 69
Microscopic Spatio-Temporal Properties of Diode Lasers......Page 70
Role of Microscopic Spatio-Temporal Properties in Macroscopic Laser Characteristics......Page 71
Optical-Field Dynamics......Page 73
Physics of the Active Semiconductor Medium......Page 77
Optical Injection......Page 81
Broad-Area Amplifier......Page 82
Tapered Amplifier......Page 84
Dynamics of Optical-Emission Characteristics......Page 85
Spatial and Spectral Carrier Dynamics......Page 87
Spatial and Spectral Refractive-Index and Gain Dynamics......Page 90
Conclusion......Page 92
References......Page 94
Epitaxy of High-Power Diode Laser Structures......Page 97
Growth Methods......Page 100
Molecular-Beam Epitaxy and Its Variants......Page 101
Metalorganic Vapor-Phase Epitaxy......Page 105
Comparison of MBE and MOVPE......Page 108
GaAs and AlGaAs......Page 110
Purity......Page 111
Purity......Page 112
Ordering......Page 113
Phase Separation......Page 115
Ordering and Phase Separation......Page 116
p-Type Doping......Page 117
Heterostructures......Page 120
Pseudomorphic Growth and Strain Relaxation......Page 121
Strain Compensation......Page 123
Device Results......Page 124
References......Page 128
GaAs Substrates for High-Power Diode Lasers......Page 135
Important Features of GaAs Crystal-Growth Methods......Page 136
Thermal Stress and Dislocation Density......Page 138
Methods of Directional Solidification: Gradient Freeze  and Bridgman Variants......Page 140
Discussion of VGF Variants......Page 143
The Hot-Wall VGF Process......Page 144
The Cold-Wall VGF Process......Page 145
GaAs Phase Diagram......Page 146
Reactions in the System GaAs, Si and B2O3......Page 147
VGF Furnace Concepts......Page 153
Preparation of Starting Materials  and Procedure of VGF Growth......Page 154
Numerical Modeling for VGF-Process Optimization......Page 155
Principles and Strategy of the Numerical Modeling......Page 156
Optimization of Growth Runs by Inverse Modeling......Page 160
Crystal and Wafer Properties......Page 168
Electrical Characterization and Silicon Doping......Page 170
Optical Characterization by Infrared  and Photoluminescence Mapping......Page 172
Distribution of Dislocations Across Wafers......Page 173
Types of Residual Dislocations in VGF-Grown GaAs......Page 176
Conclusion......Page 180
References......Page 183
High-Power Broad-Area Diode Lasers\rand Laser Bars......Page 187
The Large Optical Cavity (LOC) Concept......Page 189
AlGaAs-Waveguide Structures for Wavelengths Around 800nm......Page 190
Al-Free Waveguides for Wavelengths  from 940nm to 980nm......Page 194
Structures for Short-Wavelength Diode Lasers  from 630nm to 690nm......Page 197
Technology for Broad-Area Diode Lasers  and Laser Bars......Page 198
Implantation......Page 199
Processing of Mesa Structures......Page 201
Metallization......Page 204
Laser-Bar Preparation......Page 206
Facet Coating......Page 208
Passivation......Page 209
Reflectivity......Page 211
Influence of Heat on Laser Performance......Page 213
Simulation of Temperature Distribution......Page 215
Balance-Equation Approach......Page 216
Finite-Element Modeling......Page 221
Reliability......Page 225
Recent Results......Page 227
References......Page 232
Properties and Frequency Conversion\rof High-Brightness Diode-Laser Systems......Page 239
Beam Quality......Page 242
The Diffraction Parameter M2......Page 244
Measurement of the Wavefront......Page 246
Single-Stripe Diode Lasers......Page 249
High-Power Diode Lasers......Page 252
Diode Amplifiers......Page 253
AlGaAs Diode-MOPA Systems......Page 255
Diode-MOPA Systems Based on InGaAs......Page 259
Second-Harmonic Generation......Page 263
Diode-Pumped Optical Parametric Oscillators......Page 267
Summary......Page 270
References......Page 273
Tapered High-Power, High-Brightness\rDiode Lasers: Design and Performance......Page 279
Introduction......Page 280
Theoretical Background......Page 281
BPM Simulations......Page 283
Epitaxial Layer Structures......Page 284
Comparison of LMG and LOC Structures......Page 285
Broad-Area Diode Lasers  with LMG Layer Structures......Page 286
Fabrication of Tapered Devices......Page 287
Tapered Laser Oscillators......Page 288
Tapered Laser Amplifiers......Page 290
Tunable High-Brightness Diode-Laser Systems......Page 293
Tapered Diode-Laser Arrays......Page 296
Manufacturability......Page 298
Conclusion......Page 299
References......Page 301
Cooling and Packaging\rof High-Power Diode Lasers......Page 303
Basic Properties of Micro-Channel Coolers  for High-Power Diode Lasers......Page 305
Manufacturing and Flow Dynamics  of Cu Micro-Channel Coolers......Page 309
Packaging of Diode-Laser Bars......Page 311
References......Page 315
Introduction......Page 317
Incoherent Beam Combining......Page 323
Properties of High-Power Diode Lasers  for Direct Applications......Page 325
Beam Quality of Incoherently Combined Beams......Page 327
Technical Devices......Page 330
Beam Collimation......Page 334
Aperture Filling and Stacking Accuracy......Page 339
Applications......Page 342
Coherent Beam Combining......Page 345
Coherence Properties of Diode Lasers......Page 348
Combining of Diffraction-Limited Beams......Page 350
Multiplexing Techniques......Page 353
Phase Coupling and Beam Combining  of Single-Longitudinal-Mode Lasers......Page 359
Methods of Phase Coupling......Page 360
Prospects and Limitations of Coherent Beam Combining......Page 374
References......Page 378
Fundamental Concepts of Diode-Pumped Solid-State Lasers......Page 383
Thermal Considerations......Page 385
Fiber Lasers......Page 388
Laser-Active Waveguides......Page 389
Double-Clad Fiber Lasers......Page 391
Pump-Radiation Absorption in Double-Clad Fibers......Page 392
High-Power Laser Operation......Page 395
Fiber-Laser Emission in the Visible Spectral Region......Page 398
Thin-Disk Laser......Page 400
Design Considerations......Page 401
Numerical Simulation of the Thin-Disk Laser......Page 402
Temperature Profile within the Crystal......Page 403
Output Power and Population Inversion......Page 405
Pump Design for Eight and Sixteen Passes of Pump Radiation......Page 407
Results from the Numerical Calculations......Page 409
Experimental Results......Page 411
Power Scalability......Page 414
Other Materials than Yb:YAG......Page 416
Conclusion......Page 417
References......Page 419