Compact Blue-Green Lasers

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 7
Preface......Page 13
1.1 A SHORT HISTORICAL OVERVIEW......Page 15
1.2.1 Optical data storage......Page 17
1.2.2 Reprographics......Page 19
1.2.3 Color displays......Page 20
1.2.4 Submarine communications......Page 22
1.2.5 Spectroscopic applications......Page 26
1.2.6 Biotechnology......Page 28
REFERENCES......Page 31
2.1 INTRODUCTION......Page 34
2.2.1 The nature of the nonlinear polarization......Page 35
2.2.2 Frequencies of the induced polarization......Page 37
2.2.3 The d coefficient......Page 42
2.2.4 The generated wave......Page 44
2.2.6 Multi-longitudinal mode sources......Page 48
2.2.7.1 SHG......Page 52
2.2.7.2 SFG......Page 55
2.3.1 Boyd–Kleinman analysis for SHG with circular gaussian beams......Page 57
2.3.1.1 Experimental verification of Boyd–Kleinman theory......Page 62
2.3.1.2 Extensions of Boyd–Kleinman theory......Page 63
2.3.1.3 SFG......Page 64
2.3.2 Guided-wave SHG......Page 65
2.4.1 Introduction......Page 70
2.4.2.1 How birefringent phasematching works......Page 71
2.4.2.3 Angle tuning......Page 73
2.4.2.4 Walk-off in angle-tuned phasematching......Page 75
2.4.2.5 Effective nonlinearity......Page 78
2.4.2.6 Noncritical phasematching......Page 79
2.4.2.7 Phasematching tolerances......Page 80
2.4.2.8 The effect of nonuniformity......Page 84
2.4.3.1 How QPM works......Page 85
2.4.3.2 Fabrication of QPM structures......Page 91
2.4.3.3 Theory of QPM......Page 95
2.4.3.4 Phasematching tolerances for QPM with an ideal grating......Page 99
2.4.3.5 Imperfect QPM structures......Page 102
2.4.4.1 Modal dispersion phasematching......Page 104
2.4.4.2 Balanced phasematching......Page 107
2.4.4.3 Cerenkov phasematching......Page 108
2.4.4.4 Noncritical waveguide phasematching......Page 110
2.4.5.1 Anomalous dispersion......Page 111
2.4.5.2 Counterpropagating waves......Page 113
2.4.5.4 Form birefringence......Page 114
2.5.2.1 Birefringent phasematching......Page 115
2.5.2.2 Bulk QPM......Page 117
2.5.2.3 Waveguides......Page 118
2.5.3.3 Waveguides......Page 122
2.5.4.1 Birefringent phasematching......Page 124
2.5.4.3 Waveguides......Page 127
2.5.5.2 Bulk periodically-poled RTA (PPRTA)......Page 129
2.5.7 Potassium niobate (KN)......Page 133
2.5.7.1 Bulk KN for birefringent phasematching......Page 134
2.5.8 Potassium lithium niobate (KLN)......Page 135
2.5.9 Lithium iodate......Page 137
2.5.10.1 Birefringent phasematching......Page 138
2.5.10.2 Waveguides......Page 139
2.5.11.1 Organic materials......Page 140
2.5.11.2 Poled glasses......Page 142
2.5.11.4 Self-doubling materials......Page 143
REFERENCES......Page 144
3.1 INTRODUCTION......Page 163
3.2.1 Early experiments with gain-guided lasers......Page 165
3.2.2 Early experiments with index-guided lasers......Page 168
3.2.3 High-power index-guided narrow-stripe lasers......Page 170
3.2.4 Multiple-stripe arrays......Page 171
3.2.5 Broad-area lasers......Page 174
3.2.6.1 MOPAs using discrete devices......Page 175
3.2.6.2 Monolithically-integrated MOPA devices......Page 179
3.2.6.3 Master-oscillator–fiber-amplifiers......Page 182
3.2.7 Angled-grating distributed feedback (DFB) lasers......Page 183
3.3 SINGLE-PASS SHG OF DIODE-PUMPED SOLID-STATE LASERS......Page 184
3.3.2 Frequency-doubling of 946-nm Nd:YAG lasers......Page 191
3.4 SUMMARY......Page 192
REFERENCES......Page 193
4.1 INTRODUCTION......Page 197
4.2 THEORY OF RESONATOR ENHANCEMENT......Page 201
4.2.1 The impact of loss......Page 203
4.2.2 Impedance matching......Page 205
4.2.3 Frequency matching......Page 207
4.2.4 Approaches to frequency locking......Page 208
4.2.4.1 Electronic locking techniques......Page 209
4.2.4.2 Optical locking techniques......Page 215
4.2.5 Mode matching......Page 221
4.3.1 Temperature locking......Page 227
4.3.2 Modulation......Page 228
4.3.3 Bireflection in monolithic ring resonators......Page 229
REFERENCES......Page 234
5.1 INTRODUCTION......Page 237
5.2 THEORY OF INTRACAVITY SHG......Page 238
5.3.1 The problem itself......Page 243
5.3.2.2 Few mode operation......Page 245
5.3.3 Single-mode operation......Page 249
5.4 BLUE LASERS BASED ON INTRACAVITY SHG OF 946-nm Nd:YAG LASERS......Page 259
5.5 INTRACAVITY SHG OF Cr:LiSAF LASERS......Page 263
5.6 SELF-FREQUENCY-DOUBLING......Page 264
5.6.1 Nd:LN......Page 265
5.6.2 NYAB......Page 266
5.7 INTRACAVITY SUM-FREQUENCY MIXING......Page 267
5.8 SUMMARY......Page 269
REFERENCES......Page 270
6.1 INTRODUCTION......Page 277
6.2 FABRICATION ISSUES......Page 278
6.3 INTEGRATION ISSUES......Page 283
6.3.1 Feedback and frequency stability......Page 284
6.3.1.2 Integrated grating......Page 285
6.3.2 Polarization compatibility......Page 290
6.3.2.2 Forced TM-mode oscillation......Page 291
6.3.2.3 TE-mode doublers......Page 293
6.3.3 Coupling......Page 296
6.3.4 Control of the phasematching condition......Page 297
6.3.5 Extrinsic efficiency enhancement......Page 298
6.4 SUMMARY......Page 300
REFERENCES......Page 301
7.1 INTRODUCTION TO UPCONVERSION LASERS AND RARE-EARTH OPTICAL PHYSICS......Page 306
7.1.1 Overview of rare-earth spectroscopy......Page 309
7.1.2 Qualitative features of rare-earth spectroscopy......Page 310
7.2.1 The effective central potential......Page 317
7.2.2 Electronic structure of the free rare-earth ions......Page 320
7.2.2.2 Cerium…and the addition of angular momenta......Page 321
7.2.2.3 Ytterbium and the equivalence of electrons and holes......Page 325
7.2.2.4 Praseodymium and thulium, intermediate coupling, and the Russell–Saunders eigenstates......Page 327
7.2.2.5 The other trivalent lanthanides and Hund’s rules......Page 337
7.3 THE JUDD–OFELT EXPRESSION FOR OPTICAL INTENSITIES......Page 338
7.3.1 Basic formulation......Page 339
7.3.2 The Judd–Ofelt expression for the oscillator strength......Page 343
7.3.3 Selection rules for electric dipole transitions......Page 350
7.4 NONRADIATIVE RELAXATION......Page 352
7.5 RADIATIONLESS ENERGY TRANSFER......Page 355
7.6.1 Resonant multi-photon absorption......Page 359
7.6.2 Cooperative upconversion......Page 362
7.6.2.1 Case (i): Direct-transfer regime…......Page 364
7.6.2.2 Case (ii): Diffusion-limited regime…......Page 365
7.6.2.3 Case (iii): Hopping or diffusion regime…......Page 367
7.6.2.4 Case (iv): Ultrafast migration regime…......Page 369
7.6.3 Rate equation formulation of upconversion by radiationless energy transfer......Page 371
7.6.4 The photon avalanche......Page 374
7.7 ESSENTIALS OF LASER PHYSICS......Page 377
7.7.1 Qualitative picture......Page 378
7.7.2.1 Small signal gain......Page 379
7.7.2.2 Large-signal gain and gain saturation in a three-level amplifier......Page 381
7.7.2.3 A model laser oscillator......Page 383
7.7.2.4 Inhomogeneous broadening......Page 389
7.7.2.5 Three-level versus four-level systems......Page 392
7.8 SUMMARY......Page 396
REFERENCES......Page 397
8.1 HISTORICAL INTRODUCTION......Page 399
8.2 BULK UPCONVERSION LASERS......Page 411
8.2.1 Upconversion pumped…infrared lasers......Page 412
8.2.2.1 …transition at 550 nm......Page 424
8.2.2.2 …transition at 551 nm......Page 425
8.2.2.4 …other visible wavelengths......Page 431
8.2.3.1 …transition at ~450 nm......Page 434
8.2.3.2 …transition at ~483 nm......Page 436
8.2.3.3 …other visible wavelengths......Page 437
8.2.4 …upconversion lasers......Page 438
8.2.5 …upconversion lasers......Page 439
8.3 UPCONVERSION FIBER LASERS......Page 441
8.3.1 …transition at 556 nm......Page 447
8.3.2.1 …transition at 455 nm......Page 450
8.3.2.2 …transition at 480 nm......Page 451
8.3.2.3 Other…upconversion experiments......Page 458
8.3.3.1 …fiber lasers pumped at one wavelength......Page 459
8.3.3.2 …fiber lasers pumped at two wavelengths......Page 464
8.3.4 …transition at ~550 nm......Page 469
8.3.5 Nd…fiber lasers......Page 471
8.4 PROSPECTS......Page 472
REFERENCES......Page 474
9.1 OVERVIEW......Page 482
9.2.1 Lattice matching......Page 484
9.2.2 Epitaxial lateral overgrowth (ELOG)......Page 486
9.2.3 Basic physical parameters......Page 488
9.3 DOPING IN WIDE-GAP SEMICONDUCTORS......Page 489
9.4 OHMIC CONTACTS FOR p-TYPE WIDE-GAP SEMICONDUCTORS......Page 492
9.4.1 Ohmic contacts to p-AlGaInN......Page 493
9.4.2 New approaches to p-contacts......Page 495
9.4.3 Ohmic contacts to p-ZnSe: bandstructure engineering......Page 496
REFERENCES......Page 498
10.1 OVERVIEW OF BLUE AND GREEN DIODE LASER DEVICE ISSUES......Page 501
10.2.1 Layered design and epitaxial growth......Page 502
10.2.2 Diode laser fabrication and performance......Page 510
10.3 PHYSICS OF OPTICAL GAIN IN THE InGaN MQW DIODE LASER......Page 515
10.3.1 On the electronic microstructure of InGaN QWs......Page 520
10.3.2 Excitonic contributions in green-blue ZnSe-based QW diode lasers......Page 523
REFERENCES......Page 527
11.1 BACKGROUND......Page 531
11.2 OPTICAL RESONATOR DESIGN AND FABRICATION: DEMONSTRATION OF OPTICALLY-PUMPED VCSEL OPERATION IN THE 380–410-nm RANGE......Page 532
11.2.1 All-dielectric DBR resonator......Page 533
11.2.2 Stress engineering of AlGaN/GaN DBRs......Page 535
11.3 ELECTRICAL INJECTION: DEMONSTRATION RESONANT-CAVITY LEDs......Page 538
REFERENCES......Page 544
12 Concluding remarks......Page 547
REFERENCES......Page 550
Index......Page 551