FIBER-OPTIC COMMUNICATION SYSTEMS FOURTH EDITIONPDF电子书下载

1 Introduction 1

1.1 Historical Perspective 1

1.1.1 Need for Fiber-Optic Communications 2

1.1.2 Evolution of Lightwave Systems 4

1.2 Basic Concepts 8

1.2.1 Analog and Digital Signals 8

1.2.2 Channel Multiplexing 11

1.2.3 Modulation Formats 13

1.3 Optical Communication Systems 16

1.4 Lightwave System Components 17

1.4.1 Optical Fibers as a Communication Channel 18

1.4.2 Optical Transmitters 18

1.4.3 Optical Receivers 19

Problems 20

References 21

2 Optical Fibers 24

2.1 Geometrical-Optics Description 24

2.1.1 Step-Index Fibers 25

2.1.2 Graded-Index Fibers 27

2.2 Wave Propagation 29

2.2.1 Maxwell's Equations 29

2.2.2 Fiber Modes 31

2.2.3 Single-Mode Fibers 34

2.3 Dispersion in Single-Mode Fibers 38

2.3.1 Group-Velocity Dispersion 39

2.3.2 Material Dispersion 40

2.3.3 Waveguide Dispersion 41

2.3.4 Higher-Order Dispersion 43

2.3.5 Polarization-Mode Dispersion 44

2.4 Dispersion-Induced Limitations 46

2.4.1 Basic Propagation Equation 46

2.4.2 Chirped Gaussian Pulses 47

2.4.3 Limitations on the Bit Rate 50

2.4.4 Fiber Bandwidth 54

2.5 Fiber Losses 55

2.5.1 Attenuation Coefficient 55

2.5.2 Material Absorption 57

2.5.3 Rayleigh Scattering 58

2.5.4 Waveguide Imperfections 58

2.6 Nonlinear Optical Effects 59

2.6.1 Stimulated Light Scattering 59

2.6.2 Nonlinear Phase Modulation 64

2.6.3 Four-Wave Mixing 67

2.7 Fiber Design and Fabrication 67

2.7.1 Silica Fibers 68

2.7.2 Plastic Optical Fibers 71

2.7.3 Cables and Connectors 72

Problems 74

References 75

3 Optical Transmitters 79

3.1 Semiconductor Laser Physics 79

3.1.1 Spontaneous and Stimulated Emissions 80

3.1.2 Nonradiative Recombination 81

3.1.3 Optical Gain 82

3.1.4 Feedback and Laser Threshold 84

3.1.5 Longitudinal Modes 85

3.1.6 Laser Structures 86

3.2 Single-Mode Semiconductor Lasers 87

3.2.1 Distributed Feedback Lasers 88

3.2.2 Coupled-Cavity Semiconductor Lasers 90

3.2.3 Tunable Semiconductor Lasers 91

3.2.4 Vertical-Cavity Surface-Emitting Lasers 93

3.3 Laser Characteristics 94

3.3.1 CW Characteristics 95

3.3.2 Modulation Bandwidth 98

3.3.3 Relative Intensity Noise 100

3.3.4 Spectral Linewidth 102

3.4 Optical Signal Generation 104

3.4.1 Direct Modulation 104

3.4.2 External Modulation 106

3.5 Light-Emitting Diodes 110

3.5.1 CW Characteristics 110

3.5.2 Modulation Response 112

3.5.3 LED Structures 113

3.6 Transmitter Design 115

3.6.1 Source-Fiber Coupling 115

3.6.2 Driving Circuitry 118

3.6.3 Reliability and Packaging 119

Problems 121

References 122

4 Optical Receivers 128

4.1 Basic Concepts 128

4.1.1 Responsivity and Quantum Efficiency 128

4.1.2 Rise Time and Bandwidth 130

4.2 Common Photodetectors 131

4.2.1 p-n Photodiodes 132

4.2.2 p-i-n Photodiodes 133

4.2.3 Avalanche Photodiodes 137

4.2.4 MSM Photodetectors 143

4.3 Receiver Design 144

4.3.1 Front End 144

4.3.2 Linear Channel 145

4.3.3 Decision Circuit 147

4.3.4 Integrated Receivers 148

4.4 Receiver Noise 151

4.4.1 Noise Mechanisms 151

4.4.2 p-i-n Receivers 153

4.4.3 APD Receivers 154

4.5 Coherent Detection 158

4.5.1 Local Oscillator 158

4.5.2 Homodyne Detection 159

4.5.3 Heterodyne Detection 160

4.5.4 Signal-to-Noise Ratio 160

4.6 Receiver Sensitivity 161

4.6.1 Bit-Error Rate 162

4.6.2 Minimum Received Power 164

4.6.3 Quantum Limit of Photodetection 166

4.7 Sensitivity Degradation 167

4.7.1 Extinction Ratio 167

4.7.2 Intensity Noise 169

4.7.3 Timing Jitter 171

4.8 Receiver Performance 173

Problems 175

References 177

5 Lightwave Systems 182

5.1 System Architectures 182

5.1.1 Point-to-Point Links 182

5.1.2 Distribution Networks 184

5.1.3 Local-Area Networks 185

5.2 Design Guidelines 187

5.2.1 Loss-Limited Lightwave Systems 187

5.2.2 Dispersion-Limited Lightwave Systems 189

5.2.3 Power Budget 190

5.2.4 Rise-Time Budget 191

5.3 Long-Haul Systems 194

5.3.1 Performance-Limiting Factors 194

5.3.2 Terrestrial Lightwave Systems 196

5.3.3 Undersea Lightwave Systems 198

5.4 Sources of Power Penalty 200

5.4.1 Modal Noise 201

5.4.2 Mode-Partition Noise 202

5.4.3 Reflection Feedback and Noise 204

5.4.4 Dispersive Pulse Broadening 208

5.4.5 Frequency Chirping 209

5.4.6 Eye-Closure Penalty 210

5.5 Forward Error Correction 212

5.5.1 Error-Correcting Codes 212

5.5.2 Coding Gain 213

5.6 Computer-Aided Design 214

Problems 216

References 218

6 Multichannel Systems 223

6.1 WDM Lightwave Systems 223

6.1.1 High-Capacity Point-to-Point Links 224

6.1.2 Wide-Area and Metro-Area Networks 228

6.1.3 Multiple-Access WDM Networks 230

6.2 WDM Components 232

6.2.1 Tunable Optical Filters 233

6.2.2 Multiplexers and Demultiplexers 238

6.2.3 Add-Drop Multiplexers and Filters 242

6.2.4 Star Couplers 244

6.2.5 Wavelength Routers 246

6.2.6 WDM Transmitters and Receivers 248

6.3 System Performance Issues 251

6.3.1 Heterowavelength Linear Crosstalk 251

6.3.2 Homowavelength Linear Crosstalk 253

6.3.3 Nonlinear Raman Crosstalk 255

6.3.4 Stimulated Brillouin Scattering 257

6.3.5 Cross-Phase Modulation 259

6.3.6 Four-Wave Mixing 261

6.3.7 Other Design Issues 262

6.4 Time-Division Multiplexing 264

6.4.1 Channel Multiplexing 264

6.4.2 Channel Demultiplexing 266

6.4.3 System Performance 268

6.5 Subcarrier Multiplexing 269

6.5.1 Analog and Digital SCM Systems 270

6.5.2 Multiwavelength SCM Systems 273

6.5.3 Orthogonal Frequency-Division multiplexing 275

6.6 Code-Division Multiplexing 277

6.6.1 Time-Domain Encoding 278

6.6.2 Frequency-Domain Encoding 280

6.6.3 Frequency Hopping 281

Problems 283

References 285

7 Loss Management 295

7.1 Compensation of Fiber Losses 295

7.1.1 Periodic Amplification Scheme 296

7.1.2 Lumped Versus Distributed Amplification 298

7.1.3 Bidirectional Pumping Scheme 299

7.2 Erbium-Doped Fiber Amplifiers 300

7.2.1 Pumping and Gain Spectrum 300

7.2.2 Two-Level Model 302

7.2.3 Amplifier Noise 305

7.2.4 Multichannel Amplification 307

7.3 Raman Amplifiers 310

7.3.1 Raman Gain and Bandwidth 310

7.3.2 Raman-Induced Signal Gain 312

7.3.3 Multiple-Pump Raman Amplification 313

7.3.4 Noise Figure of Raman Amplifiers 316

7.4 Optical Signal-To-Noise Ratio 318

7.4.1 Lumped Amplification 318

7.4.2 Distributed Amplification 319

7.5 Electrical Signal-To-Noise Ratio 321

7.5.1 ASE-Induced Current Fluctuations 321

7.5.2 Impact of ASE on SNR 322

7.5.3 Noise Buildup in an Amplifier Chain 323

7.6 Receiver Sensitivity and Q Factor 325

7.6.1 Bit-Error Rate 325

7.6.2 Relation between Q Factor and Optical SNR 327

7.7 Role of Dispersive and Nonlinear Effects 328

7.7.1 Noise Growth through Modulation Instability 328

7.7.2 Noise-Induced Signal Degradation 330

7.7.3 Noise-Induced Energy Fluctuations 332

7.7.4 Noise-Induced Timing Jitter 333

7.8 Periodically Amplified Lightwave Systems 334

7.8.1 Numerical Approach 335

7.8.2 Optimum Launched Power 337

Problems 339

References 340

8 Dispersion Management 345

8.1 Dispersion Problem and Its Solution 345

8.2 Dispersion-Compensating Fibers 347

8.2.1 Conditions for Dispersion Compensation 348

8.2.2 Dispersion Maps 349

8.2.3 DCF Designs 350

8.3 Fiber Bragg Gratings 354

8.3.1 Constant-Period Gratings 354

8.3.2 Chirped Fiber Gratings 356

8.3.3 Sampled Gratings 360

8.4 Dispersion-Equalizing Filters 363

8.4.1 Gires-Tournois Filters 363

8.4.2 Mach-Zehnder Filters 366

8.4.3 Other All-Pass Filters 367

8.5 Optical Phase Conjugation 369

8.5.1 Principle of Operation 369

8.5.2 Compensation of Self-Phase Modulation 370

8.5.3 Generation of Phase-Conjugated Signal 371

8.6 Channels at High Bit Rates 375

8.6.1 Tunable Dispersion Compensation 375

8.6.2 Higher-Order Dispersion Management 379

8.6.3 PMD Compensation 382

8.7 Electronic Dispersion Compensation 385

8.7.1 Basic Idea behind GVD Precompensation 385

8.7.2 Precompensation at the Transmitter 386

8.7.3 Dispersion Compensation at the Receiver 392

Problems 397

References 399

9 Control of Nonlinear Effects 407

9.1 Impact of Fiber Nonlinearity 407

9.1.1 System Design Issues 408

9.1.2 Semianalytic Approach 411

9.1.3 Soliton and Pseudo-linear Regimes 414

9.2 Solitons in Optical Fibers 416

9.2.1 Properties of Optical Solitons 416

9.2.2 Loss-Managed Solitons 419

9.3 Dispersion-Managed Solitons 423

9.3.1 Dispersion-Decreasing Fibers 423

9.3.2 Periodic Dispersion Maps 424

9.3.3 Design Issues 427

9.3.4 Timing Jitter 430

9.3.5 Control of Timing Jitter 432

9.4 Pseudo-linear Lightwave Systems 434

9.4.1 Origin of Intrachannel Nonlinear Effects 435

9.4.2 Intrachannel Cross-Phase Modulation 437

9.4.3 Intrachannel Four-Wave Mixing 441

9.5 Control of Intrachannel Nonlinear Effects 444

9.5.1 Optimization of Dispersion Maps 444

9.5.2 Phase-Alternation Techniques 448

9.5.3 Polarization Bit Interleaving 449

Problems 451

References 453

10 Advanced Lightwave Systems 459

10.1 Advanced Modulation Formats 460

10.1.1 Encoding of Optical Signals 460

10.1.2 Amplitude and Phase Modulators 462

10.2 Demodulation Schemes 464

10.2.1 Synchronous Heterodyne Demodulation 464

10.2.2 Asynchronous Heterodyne Demodulation 466

10.2.3 Optical Delay Demodulation 467

10.3 Shot Noise and Bit-Error Rate 470

10.3.1 Synchronous Heterodyne Receivers 470

10.3.2 Asynchronous Heterodyne Receivers 472

10.3.3 Receivers with Delay Demodulation 475

10.4 Sensitivity Degradation Mechanisms 476

10.4.1 Intensity Noise of Lasers 476

10.4.2 Phase Noise of Lasers 478

10.4.3 Signal Polarization Fluctuations 480

10.4.4 Noise Added by Optical Amplifiers 483

10.4.5 Fiber Dispersion 484

10.5 Impact of Nonlinear Effects 485

10.5.1 Nonlinear Phase Noise 486

10.5.2 Effect of Fiber Dispersion 489

10.5.3 Compensation of Nonlinear Phase Noise 490

10.6 Recent Progress 494

10.6.1 Systems with the DBPSK format 494

10.6.2 Systems with the DQPSK format 496

10.6.3 QAM and Related formats 497

10.6.4 Systems Employing Orthogonal FDM 499

10.7 Ultimate Channel Capacity 501

Problems 503

References 504

11 Optical Signal Processing 511

11.1 Nonlinear Techniques and Devices 511

11.1.1 Nonlinear Optical Loop Mirrors 512

11.1.2 Parametric Amplifiers 516

11.1.3 Nonlinear Effects in Semiconductor Optical Amplifiers 522

11.1.4 Bistable Optical Devices 526

11.2 All-Optical Flip-Flops 529

11.2.1 Semiconductor Lasers and SOAs 529

11.2.2 Coupled Semiconductor Lasers and SOAs 531

11.3 Wavelength Converters 533

11.3.1 XPM-Based Wavelength Converters 533

11.3.2 FWM-Based Wavelength Converters 537

11.3.3 Passive Semiconductor Waveguides 540

11.3.4 SOA-Based Wavelength Converters 542

11.4 Ultrafast Optical Switching 544

11.4.1 Time-Domain Demultiplexing 545

11.4.2 Data-Format Conversion 549

11.4.3 Packet Switching 552

11.5 Optical Regenerators 553

11.5.1 Fiber-Based 2R Regenerators 553

11.5.2 SOA-Based 2R Regenerators 559

11.5.3 Fiber-Based 3R Regenerators 560

11.5.4 SOA-Based 3R Regenerators 562

11.5.5 Regeneration of Phase-Encoded Signals 565

Problems 568

References 569

A System of Units 578

B Acronyms 580

C General Formula for Pulse Broadening 584

D Software Package 587

Index 589