Semiconductor Devices for High-Speed Optoelectronics

Cover......Page 1
Half-title......Page 3
Title......Page 5
Copyright......Page 6
Dedication......Page 7
Contents......Page 9
Preface......Page 15
1.1 Introducing semiconductors......Page 19
1.2 Semiconductor crystal structure......Page 20
1.2.1 The Miller index notation......Page 21
1.2.2 The diamond, zinc-blende, and wurtzite semiconductor cells......Page 23
1.2.3 Ferroelectric crystals......Page 24
1.2.4 Crystal defects......Page 25
1.3.1 The energy–momentum dispersion relation......Page 26
1.3.2 The conduction and valence band wavefunctions......Page 30
1.3.3 Direct- and indirect-bandgap semiconductors......Page 31
1.4.1 Equilibrium electron and hole densities......Page 35
1.4.2 Electron and hole densities in doped semiconductors......Page 38
1.4.3 Nonequilibrium electron and hole densities......Page 39
1.5 Heterostructures......Page 42
1.6 Semiconductor alloys......Page 43
1.6.1 The substrate issue......Page 45
1.6.2 Important compound semiconductor alloys......Page 46
1.7 Bandstructure engineering: heterojunctions and quantum wells......Page 47
1.7.1 Carrier density and density of states in a quantum well......Page 51
1.7.2 Carrier density and density of states in a quantum wire......Page 56
1.7.4 Effect of strain on bandstructure......Page 58
1.8.1 Drift and diffusion......Page 60
1.8.2 Generation and recombination......Page 61
1.8.3 Trap-assisted (Shockley–Read–Hall) recombination......Page 62
1.8.4 Auger recombination and generation by impact ionization......Page 64
1.9.1 Questions......Page 66
1.9.2 Problems......Page 68
2.1 Modeling the interaction between EM waves and the semiconductor......Page 70
2.2 The macroscopic view: permittivities and permeabilities......Page 71
2.2.1 Isotropic vs. anisotropic media......Page 76
2.3 The microscopic view: EM wave–semiconductor interaction......Page 77
2.3.1 Energy and momentum conservation......Page 79
2.3.2 Perturbation theory and selection rules......Page 86
2.3.3 Total scattering rates......Page 92
2.4 The macroscopic view: the EM wave standpoint......Page 96
2.4.1 The semiconductor gain energy profile......Page 98
2.4.2 The semiconductor absorption energy profile......Page 101
2.4.3 The QW absorption profile......Page 102
2.4.4 Spontaneous emission spectrum......Page 107
2.4.5 Spontaneous emission, gain, and absorption spectra......Page 109
2.5 The macroscopic view: the semiconductor standpoint......Page 111
2.5.1 Carrier radiative lifetimes......Page 113
2.6.1 Questions......Page 119
2.6.2 Problems......Page 120
3.2 Transmission lines......Page 122
3.2.1 RG, RC, and high-frequency regimes......Page 127
3.2.2 The reflection coefficient and the loaded line......Page 129
3.2.3 Planar integrated quasi-TEM transmission lines......Page 131
3.2.4 Microstrip lines......Page 132
3.2.5 Coplanar lines......Page 133
3.3 The scattering parameters......Page 135
3.3.1 Power and impedance matching......Page 137
3.4 Passive concentrated components......Page 139
3.4.1 Bias Ts......Page 142
3.5.1 Field-effect transistors (FETs)......Page 144
3.5.2 FET DC model......Page 146
3.5.3 FET small-signal model and equivalent circuit......Page 148
3.5.4 High-speed FETs: the HEMT family......Page 151
3.5.5 High-speed heterojunction bipolar transistors......Page 159
3.5.6 HBT equivalent circuit......Page 161
3.5.7 HBT choices and material systems......Page 163
3.6 Noise in electron devices......Page 165
3.6.1 Equivalent circuit of noisy N-ports......Page 166
3.6.2 Noise models of active and passive devices......Page 167
3.7 Monolithic and hybrid microwave integrated circuits and optoelectronic integrated circuits......Page 169
3.8.1 Questions......Page 173
3.8.2 Problems......Page 175
4.1 Photodetector basics......Page 176
4.2 Photodetector structures......Page 177
4.3 Photodetector materials......Page 179
4.4.1 PD constitutive relation......Page 183
4.4.2 Responsivity and quantum efficiency......Page 185
4.4.3 PD electrical bandwidth and equivalent circuit......Page 189
4.5 Photodetector noise......Page 192
4.6 Photodiodes......Page 196
4.7 The pn photodiode......Page 197
4.7.1 Analysis of the pn photodiode response......Page 198
4.8 The pin photodiode......Page 202
4.8.1 The pin photocurrent, responsivity, and efficiency......Page 203
4.8.2 Conventional pin photodetector structures......Page 206
4.9 The pin frequency response......Page 207
4.9.1 Carrier diffusion and heterojunction charge trapping......Page 208
4.9.2 Dynamic pin model and space-charge effects......Page 209
4.9.3 Transit time analysis and transit time-limited bandwidth......Page 211
4.9.4 Capacitance-limited bandwidth......Page 215
4.9.5 Bandwidth–efficiency trade-off......Page 217
4.10 Advanced pin photodiodes......Page 218
4.10.1 Waveguide photodiodes......Page 219
4.10.2 Traveling-wave photodetectors......Page 221
4.10.3 Velocity-matched traveling-wave photodetectors......Page 227
4.10.4 Uni-traveling carrier photodiodes......Page 228
4.11 Avalanche photodiodes......Page 229
4.11.1 Analysis of APD responsivity......Page 231
4.12 Noise in APDs and pins......Page 238
4.12.1 Analysis of APD noise......Page 240
4.13 The APD frequency response......Page 246
4.14 Advanced APD structures......Page 249
4.15 Concluding remarks on high-speed PDs......Page 250
4.16 The photodiode front end......Page 251
4.16.2 High- and low-impedance front ends......Page 252
4.16.3 Transimpedance amplifier front ends......Page 254
4.16.4 High-speed transimpedance stages......Page 258
4.17 Front-end SNR analysis and pin–APD comparison......Page 260
4.18 Front-end examples......Page 265
4.18.1 Hybrid and monolithic front-end solutions......Page 268
4.19.1 Questions......Page 269
4.19.2 Problems......Page 271
5.2 Light-emitting diodes......Page 273
5.2.1 LED structures......Page 274
5.2.2 Homojunction LED power–current characteristics......Page 275
5.2.3 Charge control model and modulation bandwidth......Page 278
5.2.4 Heterojunction LED analysis......Page 279
5.2.5 LED emission spectrum......Page 280
5.2.6 LED materials......Page 282
5.3 From LED to laser......Page 283
5.4 The Fabry–Perot cavity resonant modes......Page 286
5.4.1 Analysis of the TE slab waveguide fundamental mode......Page 287
5.4.2 Longitudinal and transversal cavity resonances......Page 290
5.5.1 Analysis of the overlap integral......Page 293
5.6 The FP laser from below to above threshold......Page 296
5.6.1 The threshold condition......Page 297
5.6.2 The emission spectrum......Page 299
5.6.3 The electron density and optical power......Page 300
5.6.5 The photon lifetimes......Page 301
5.6.6 Power–current characteristics from photon lifetimes......Page 302
5.7 The laser evolution: tailoring the active region......Page 303
5.7.1 Quantum-well lasers......Page 304
5.8 The laser evolution: improving the spectral purity and stability......Page 308
5.8.2 Gain-guided FP lasers......Page 309
5.8.3 Index-guided FP lasers......Page 310
5.8.4 Distributed-feedback (DFB and DBR) lasers......Page 312
5.8.5 DBR and tunable DBR lasers......Page 317
5.8.6 Vertical cavity lasers......Page 318
5.8.7 Quantum dot lasers......Page 320
5.9 The laser temperature behavior......Page 321
5.10 Laser linewidth......Page 322
5.10.1 Linewidth broadening analysis......Page 324
5.11 Laser dynamics and modulation response......Page 333
5.12 Dynamic large-signal and small-signal laser modeling......Page 339
5.12.1 Steady-state (DC) solution......Page 341
5.12.2 Small-signal model......Page 343
5.12.3 Chirp analysis......Page 347
5.13 Laser relative intensity noise......Page 348
5.13.1 Analysis of Langevin sources......Page 349
5.13.2 Carrier and photon population fluctuations......Page 356
5.13.3 Output power fluctuations......Page 358
5.13.4 Relative intensity noise......Page 361
5.13.5 Phase noise and linewidth from the Langevin approach......Page 364
5.14.1 Questions......Page 370
5.14.2 Problems......Page 371
6.1 Light modulation and modulator choices......Page 374
6.2.1 Electrooptic (static) response......Page 376
6.2.3 Small-signal frequency response......Page 378
6.2.4 Optical and electrical modulation bandwidth......Page 380
6.2.8 Linearity and distortion......Page 381
6.3 Electrooptic modulators......Page 382
6.3.1 Lithium niobate electrooptic modulators......Page 383
6.3.2 Semiconductor electrooptic modulators......Page 390
6.3.3 Polymer modulators......Page 392
6.4 The Mach–Zehnder electrooptic modulator......Page 393
6.4.1 The lumped Mach–Zehnder modulator......Page 394
6.4.2 Static electrooptic response......Page 395
6.4.3 Lumped modulator dynamic response......Page 396
6.4.4 Efficiency–bandwidth trade-off in lumped MZ modulators......Page 398
6.5 The traveling-wave Mach–Zehnder modulator......Page 400
6.5.1 Mach–Zehnder traveling-wave modulator dynamic response......Page 401
6.5.2 Analysis of the TW Mach–Zehnder modulator response......Page 405
6.5.3 The Mach–Zehnder modulator chirp......Page 409
6.6 High-speed electrooptic modulator design......Page 412
6.6.1 Lithium niobate modulators......Page 414
6.6.2 Compound semiconductor, polymer, and silicon modulators......Page 417
6.7 Electroabsorption modulator physics......Page 420
6.7.1 The Franz–Keldysh effect (FKE)......Page 421
6.7.2 The quantum confined Stark effect (QCSE)......Page 422
6.8 Electroabsorption modulator structures and parameters......Page 427
6.8.1 EAM static response......Page 428
6.8.2 Lumped EAM dynamic response......Page 430
6.8.3 EAM chirp......Page 432
6.9 The distributed electroabsorption modulator......Page 433
6.10 Electroabsorption modulator examples......Page 438
6.10.1 Integrated EAMs (EALs)......Page 441
6.11 Modulator and laser biasing......Page 443
6.12 Modulator and laser drivers......Page 445
6.12.1 The high-speed driver amplifier......Page 448
6.13.1 Questions......Page 454
6.13.2 Problems......Page 456
Symbols......Page 458
References......Page 468
Index......Page 475