激光原理 第4版PDF电子书下载

1.Introductory Concepts 1

1.1.Spontaneous and Stimulated Emission，Absorption 2

1.2.The Laser Idea 4

1.3.Pumping Schemes 7

1.4.Properties of Laser Beams 9

1.4.1.Monochromaticity 9

1.4.2.Coherence 9

1.4.3.Directionality 10

1.4.4.Brightness 11

1.4.5.Short Pulse Duration 13

1.5.Laser Types 14

Problems 14

2.Interaction of Radiation with Atoms and Ions 17

2.1.Introduction 17

2.2.Summary of Blackbody Radiation Theory 17

2.2.1.Modes of a Rectangular Cavity 19

2.2.2.Rayleigh-Jeans and Planck Radiation Formula 22

2.2.3.Planck’s Hypothesis and Field Quantization 23

2.3.Spontaneous Emission 25

2.3.1.Semiclassical Approach 26

2.3.2.Quantum Electrodynamics Approach 29

2.3.3.Allowed and Forbidden Transitions 31

2.4.Absorption and Stimulated Emission 32

2.4.1.Absorption and Stimulated Emission Rates 32

2.4.2.Allowed and Forbidden Transitions 36

2.4.3.Transition Cross Section， Absorption，and Gain Coefficient 37

2.4.4.Einstein Thermodynamic Treatment 42

2.5.Line-Broadening Mechanisms 43

2.5.1.Homogeneous Broadening 44

2.5.2.Inhomogeneous Broadening 48

2.5.3.Concluding Remarks 49

2.6.Nonradiative Decay and Energy Transfer 50

2.6.1.Mechanisms of Nonradiative Decay 50

2.6.2.Combined Effects of Radiative and Nonradiative Processes 56

2.7.Degenerate or Strongly Coupled Levels 58

2.7.1.Degenerate Levels 58

2.7.2.Strongly Coupled Levels 60

2.8.Saturation 64

2.8.1.Saturation of Absorption： Homogeneous Line 64

2.8.2.Gain Saturation： Homogeneous Line 68

2.8.3.Inhomogeneously Broadened Line 69

2.9.Fluourescence Decay of an Optically Dense Medium 71

2.9.1.Radiation Trapping 71

2.9.2.Amplified Spontaneous Emission 71

2.10.Concluding Remarks 76

Problems 77

References 78

3.Energy Levels.Radiative.and Nonradiative Transitions in Molecules and Semiconductors 81

3.1.Molecules 81

3.1.1.Energy Levels 81

3.1.2.Level Occupation at Thermal Equilibrium 85

3.1.3.Stimulated Transitions 87

3.1.4.Radiative and Nonradiative Decay 91

3.2.Bulk Semiconductors 92

3.2.1.Electronic States 92

3.2.2.Density of States 96

3.2.3.Level Occupation at Thermal Equilibrium 97

3.2.4.Stimulated Transitions：Selection Rules 101

3.2.5.Absorption and Gain Coefficients 103

3.2.6.Spontaneous Emission and Nonradiative Decay 109

3.2.7.Concluding Remarks 111

3.3.Semiconductor Quantum Wells 112

3.3.1.Electronic States 112

3.3.2.Density of States 115

3.3.3.Level Occupation at Thermal Equilibrium 117

3.3.4.Stimulated Transitions： Selection Rules 118

3.3.5.Absorption and Gain Coefficients 120

3.3.6.Strained Quantum Wells 123

3.4.Quantum Wires and Quantum Dots 125

3.5.Concluding Remarks 126

Problems 127

References 128

4.Ray and Wave Propagation through Optical Media 129

4.1.Introduction 129

4.2.Matrix Formulation of Geometric Optics 129

4.3.Wave Reflection and Transmission at a Dielectric Interface 135

4.4.Multilayer Dielectric Coatings 137

4.5.Fabry-Perot Interferometer 140

4.5.1.Properties of a Fabry-Perot Interferometer 140

4.5.2.Fabry-Perot Interferometer as a Spectrometer 144

4.6.Diffraction Optics in the Paraxial Approximation 145

4.7.Gaussian Beams 148

4.7.1.Lowest Order Mode 148

4.7.2.Free-Space Propagation 151

4.7.3.Gaussian Beams and ABCD Law 154

4.7.4.Higher Order Modes 155

4.8.Conclusions 158

Problems 158

References 160

5.Passive Optical Resonators 161

5.1.Introduction 161

5.1.1.Plane Parallel（Fabry-Perot） Resonator 162

5.1.2.Concentric （Spherical） Resonator 163

5.1.3.Confocal Resonator 163

5.1.4.Generalized Spherical Resonator 163

5.1.5.Ring Resonator 164

5.2.Eigenmodes and Eigenvalues 165

5.3.Photon Lifetime and Cavity Q 167

5.4.Stability Condition 169

5.5.Stable Resonators 173

5.5.1.Resonators with Infinite Aperture 173

5.5.1.1.Eigenmodes 174

5.5.1.2.Eigenvalues 178

5.5.1.3.Standing and Traveling Waves in a Two-Mirror Resonator 180

5.5.2.Effects of a Finite Aperture 181

5.5.3.Dynamically and Mechanically Stable Resonators 184

5.6.Unstable Resonators 187

5.6.1.Geometric Optics Description 188

5.6.2.Wave Optics Description 190

5.6.3.Advantages and Disadvantages of Hard-Edge Unstable Resonators 193

5.6.4.Unstable Resonators with Variable-Reflectivity Mirrors 194

5.7.Concluding Remarks 198

Problems 198

References 200

6.Pumping Processes 201

6.1.Introduction 201

6.2.Optical Pumping by an Incoherent Light Source 204

6.2.1.Pumping Systems 204

6.2.2.Pump Light Absorption 206

6.2.3.Pump Efficiency and Pump Rate 208

6.3.Laser Pumping 210

6.3.1.Laser-Diode Pumps 212

6.3.2.Pump Transfer Systems 214

6.3.2.1.Longitudinal Pumping 214

6.3.2.2.Transverse Pumping 219

6.3.3.Pump Rate and Pump Efficiency 221

6.3.4.Threshold Pump Power for Four-Level and Quasi-Three-Level Lasers 223

6.3.5.Comparison between Diode Pumping and Lamp Pumping 226

6.4.Electrical Pumping 228

6.4.1.Electron Impact Excitation 231

6.4.1.1.Electron Impact Cross Section 232

6.4.2.Thermal and Drift Velocities 235

6.4.3.Electron Energy Distribution 237

6.4.4.Ionization Balance Equation 240

6.4.5.Scaling Laws for Electrical Discharge Lasers 241

6.4.6.Pump Rate and Pump Efficiency 242

6.5.Conclusions 244

Problems 244

References 247

7.Continuous Wave Laser Behavior 249

7.1.Introduction 249

7.2.Rate Equations 249

7.2.1.Four-Level Laser 250

7.2.2.Quasi-Three-Level Laser 255

7.3.Threshold Conditions and Output Power：Four-Level Laser 258

7.3.1.Space-Independent Model 258

7.3.2.Space-Dependent Model 265

7.4.Threshold Condition and Output Power：Quasi-Three-Level Laser 273

7.4.1.Space-Independent Model 273

7.4.2.Space-Dependent Model 274

7.5.Optimum Output Coupling 277

7.6.Laser Tuning 279

7.7.Reasons for Multimode Oscillation 281

7.8.Single-Mode Selection 284

7.8.1.Single-Transverse-Mode Selection 284

7.8.2.Single-Longitudinal-Mode Selection 285

7.8.2.1.Fabry-Perot Etalons as Mode-Selective Elements 285

7.8.2.2.Single-Mode Selection in Unidirectional Ring Resonators 288

7.9.Frequency Pulling and Limit to Monochrornaticity 291

7.10.Laser Frequency Fluctuations and Frequency Stabilization 293

7.11.Intensity Noise and Intensity Noise Reduction 297

7.12.Conclusions 300

Problems 301

References 303

8.Transient Laser Behavior 305

8.1.Introduction 305

8.2.Relaxation Oscillations 305

8.3.Dynamic Instabilities and Pulsations in Lasers 310

8.4.Q-Switching 311

8.4.1.Dynamics of the Q-Switching Process 311

8.4.2.Q-Switching Methods 313

8.4.2.1.Electrooptical Q-Switching 313

8.4.2.2.Rotating Prisms 315

8.4.2.3.Acoustooptic Q-Switches 316

8.4.2.4.Saturable Absorber Q-Switch 317

8.4.3.Operating Regimes 319

8.4.4.Theory of Active Q-Switching 321

8.5.Gain Switching 329

8.6.Mode Locking 330

8.6.1.Frequency-Domain Description 331

8.6.2.Time-Domain Picture 336

8.6.3.Mode-Locking Methods 337

8.6.3.1.Active Mode Locking 337

8.6.3.2.Passive Mode Locking 342

8.6.4.Role of Cavity Dispersion in Femtosecond Mode-Locked Lasers 347

8.6.4.1.Phase Velocity，Group Velocity，and Group-Delay Dispersion 347

8.6.4.2.Limitation on Pulse Duration Due to Group-Delay Dispersion 350

8.6.4.3.Dispersion Compensation 351

8.6.4.4.Soliton-Type Mode Locking 353

8.6.5.Mode-Locking Regimes and Mode-Locking System 355

8.7.Cavity Dumping 359

8.8.Concluding Remarks 361

Problems 361

References 363

9.Solid-State，Dye，and Semiconductor Lasers 365

9.1.Introduction 365

9.2.Solid-State Lasers 365

9.2.1.Ruby Laser 367

9.2.2.Neodymium Lasers 370

9.2.2.1.Nd：YAG Laser 370

9.2.2.2.Nd：Glass Laser 373

9.2.2.3.Other Crystalline Hosts 373

9.2.3.Yb：YAG Laser 374

9.2.4.Er：YAG and Yb：Er：Glass Lasers 376

9.2.5.Tm：Ho：YAG Laser 377

9.2.6.Fiber Lasers 378

9.2.7.Alexandrite Laser 381

9.2.8.Titanium Sapphire Laser 383

9.2.9.Cr：LiSAF and Cr：LiCAF Lasers 385

9.3.Dye Lasers 386

9.3.1.Photophysical Properties of Organic Dyes 387

9.3.2.Characteristics of Dye Lasers 391

9.4.Semiconductor Lasers 394

9.4.1.Principle of Semiconductor Laser Operation 394

9.4.2.Homojunction Lasers 396

9.4.3.Double-Heterostructure Lasers 398

9.4.4.Quantum Well Lasers 402

9.4.5.Laser Devices and Performances 405

9.4.6.Distributed Feedback and Distributed Bragg Reflector Lasers 408

9.4.7.Vertical-Cavity Surface-Emitting Lasers 411

9.4.8.Semiconductor Laser Applications 413

9.5.Conclusions 415

Problems 415

References 417

10.Gas，Chemical，Free-Electon，and X-Ray Lasers 419

10.1.Introduction 419

10.2.Gas Lasers 419

10.2.1.Neutral Atom Lasers 420

10.2.1.1.Helium Neon Laser 420

10.2.1.2.Copper Vapor Laser 425

10.2.2.Ion Lasers 427

10.2.2.1.Argon Laser 427

10.2.2.2.He-Cd Laser 430

10.2.3.Molecular Gas Lasers 432

10.2.3.1.CO2 Laser 432

10.2.3.2.CO Laser 442

10.2.3.3.Nitrogen Laser 444

10.2.3.4.Excimer Lasers 445

10.3.Chemical Lasers 448

10.4.Free-Electron Lasers 452

10.5.X-Ray Lasers 456

10.6.Concluding Remarks 458

Problems 459

References 460

11.Properties of Laser Beams 463

11.1.Introduction 463

11.2.Monochromaticity 463

11.3.First-Order Coherence 464

11.3.1.Degree of Spatial and Temporal Coherence 464

11.3.2.Measurement of Spatial and Temporal Coherence 468

11.3.3.Relation between Temporal Coherence and Monochromaticity 471

11.3.4.Nonstationary Beams 473

11.3.5.Spatial and Temporal Coherence of Single-Mode and Multimode Lasers 473

11.3.6.Spatial and Temporal Coherence of a Thermal Light Source 475

11.4.Directionality 476

11.4.1.Beams with Perfect Spatial Coherence 477

11.4.2.Beams with Partial Spatial Coherence 479

11.4.3.The M2 Factor and the Spot Size Parameter of a Multimode Laser Beam 480

11.5.Laser Speckle 483

11.6.Brightness 486

11.7.Statistical Properties of Laser Light and Thermal Light 487

11.8.Comparison between Laser Light and Thermal Light 489

Problems 491

References 492

12.Laser Beam Transformation：Propagation，Amplification，Frequency Conversion，Pulse Compression，and Pulse Expansion 493

12.1.Introduction 493

12.2.Spatial Transformation：Propagation of a Multimode Laser Beam 494

12.3.Amplitude Transformation：Laser Amplification 495

12.3.1.Examples of Laser Amplifiers： Chirped-Pulse-Amplification 500

12.4.Frequency Conversion： Second-Harmonic Generation and Parametric Oscillation 504

12.4.1.Physical Picture 504

12.4.1.1.Second Harmonic Generation 505

12.4.1.2.Parametric Oscillation 512

12.4.2.Analytical Treatment 514

12.4.2.1.Parametric Oscillation 516

12.4.2.2.Second-Harmonic Generation 520

12.5.Transformation in Time 523

12.5.1.Pulse Compression 524

12.5.2.Pulse Expansion 529

Problems 530

References 532

Appendixes 535

A.Semiclassical Treatment of the Interaction of Radiation and Matter 535

B.Lineshape Calculation for Collision Broadening 541

C.Simplified Treatment of Amplified Spontaneous Emission 545

References 548

D.Calculation of the Radiative Transition Rates of Molecular Transitions 549

E.Space-Dependent Rate Equations 553

E.1.Four-Level Lasers 553

E.2.Quasi-Three-Level Lasers 559

F.Mode-Locking Theory：Homogeneous Line 563

F.1.Active Mode Locking 563

F.2.Passive Mode Locking 568

References 569

G.Propagation of a Laser Pulse through a Dispersive Medium or a Gain Medium 571

Reference 575

H.Higher-Order Coherence 577

I.Physical Constants and Useful Conversion Factors 581

Answers to Selected Problems 583

Index 595