1. WAVE NATURE OF LIGHT 1
1.1 Light Waves in a Homogeneous Medium 1
A. Plane Electromagnetic Wave 1
B. Maxwells Wave Equation and Diverging Waves 4
Example 1.1.1:A diverging laser beam 7
1.2 Refractive Index 7
Example 1.2.1: Relative permittivity and refractive index 8
1.3 Group Velocity and Group Index 9
Example 1.3.1: Group velocity 11
Example 1.3.2: Group and phase velocities 11
1.4 Magnetic Field, Irradiance, and Poynting Vector 11
Example 1.4.1: Electric and magnetic fields in light 13
1.5 Snells Law and Total Internal Reection (TIR) 14
1.6 Fresnels Equations 16
A. Amplitude Reection and Transmission Coefficients 16
Example 1.6.1: Evanescent wave 22
B. Intensity, Reectance, and Transmittance 23
Example 1.6.2: Reection of light from a less dense medium 24
Example 1.6.3: Reection at normal incidence. Internal andexternal reection 25
Example 1.6.4: Antireection coatings on solar cells 26
Example 1.6.5: Dielectric mirrors 27
1.7 Multiple Interference and Optical Resonators 28
Example 1.7.1: Resonator modes and spectral width 31
1.8 Goos-Hanchen Shift and Optical Tunneling 32
1.9 Temporal and Spatial Coherence 34
1.10 Diffraction Principles 37
A. Fraunhofer Diffraction 37
Example 1.10.1: Resolving power of imaging systems 41
B. Diffraction grating 42
Questions and Problems 44
2. DIELECTRIC WAVEGUIDES AND OPTICAL FIBERS 50
2.1 Symmetric Planar Dielectric Slab Waveguide 50
A. Waveguide Condition 50
B. Single and Multimode Waveguides 55
C. TE and TM Modes 56
Example 2.1.1: Waveguide modes 57
Example 2.1.2: V-number and the number of modes 58
Example 2.1.3: Mode field distance (MFD) 59
2.2 Modal and Waveguide Dispersion in the Planar Waveguide 60
A. Waveguide Dispersion Diagram 60
B. Intermodal Dispersion 60
C. Intramodal Dispersion 62
2.3 Step Index Fiber 63
Example 2.3.1: A multimode fiber 68
Example 2.3.2: A single mode fiber 68
Example 2.3.3: Single mode cut-off wavelength 68
Example 2.3.4: Group velocity and delay 69
2.4 Numerical Aperture 69
Example 2.4.1: A multimode fiber and total acceptance angle 71
Example 2.4.2: A single mode fiber 71
2.5 Dispersion in Single Mode Fibers 71
A. Material Dispersion 71
B. Waveguide Dispersion 73
C. Chromatic Dispersion or Total Dispersion 74
D. Profile and Polarization Dispersion Effects 75
E. Dispersion Flattened Fibers 76
Example 2.5.1: Material dispersion 77
Example 2.5.2: Material, waveguide, and chromatic dispersion 77
2.6 Bit-Rate, Dispersion, Electrical, and Optical Bandwidth 78
A. Bit-Rate and Dispersion 78
B. Optical and Electrical Bandwidth 81
Example 2.6.1: Bit-rate and dispersion 82
2.7 The Graded Index Optical Fiber 83
Example 2.7.1: Dispersion in a graded-index fiber and bit-rate 85
2.8 Light Absorption and Scattering 87
A. Absorption 87
B. Scattering 88
2.9 Attenuation in Optical Fibers 90
Example 2.9.1: Rayleigh scattering limit 93
Example 2.9.2: Attenuation along an optical ber 94
2.10 Fiber Manufacture 94
A. Fiber Drawing 94
B. Outside Vapor Deposition (OVD) 96
Example 2.10.1: Fiber drawing 98
Questions and Problems 98
3. SEMICONDUCTOR SCIENCE AND LIGHT EMIING DIODES 107
3.1 Semiconductor Concepts and Energy Bands 107
A. Energy Band Diagrams 107
B. Semiconductor Statistics 110
C. Extrinsic Semiconductors 113
D. Compensation Doping 116
E. Degenerate and Nondegenerate Semiconductors 117
F Energy Band Diagrams in an Applied Field 118
Example 3.1.1: Fermi levels in semiconductors 118
Example 3.1.2: Conductivity 119
3.2 Direct and Indirect Bandgap Semiconductors: E-k Diagrams 119
3.3 pn Junction Principles 123
A. Open Circuit 123
B. Forward Bias 126
C. Reverse Bias 131
D. Depletion Layer Capacitance 134
E. Recombination Lifetime 135
Example 3.3.1: A direct band gap pn junction 136
3.4 The pn Junction Band Diagram 137
A. Open Circuit 137
B. Forward and Reverse Bias 138
3.5 Light Emitting Diodes 139
A. Principles 139
B. Device Structures 141
3.6 LED Materials 142
3.7 Heterojunction High Intensity LEDS 144
3.8 LED Characteristics 147
Example 3.8.1: LED output spectrum 149
Example 3.8.2: LED output wavelength variations 149
Example 3.8.3: InGaAsP on InP substrate 150
3.9 LEDs for Optical Fiber Communications 150
Questions and Problems 153
4. STIMULATED EMISSION DEVICES LASERS 159
4.1 Stimulated Emission and Photon Amplification 159
4.2 Stimulated Emission Rate and Einstein Coefficients 162
4.3 Optical Fiber Amplifiers 164
4.4 Gas Laser: The He-Ne Laser 166
Example 4.4.1: Efficiency of the He-Ne laser 169
Example 4.4.2: Laser beam divergence 170
4.5 The Output Spectrum of a Gas Laser 170
Example 4.5.1: Doppler broadened linewidth 173
4.6 LASER Oscillation Conditions 174
A. Optical Gain Coefficient g 174
B. Threshold Gain gth 176
C. Phase Condition and Laser Modes 178
Example 4.6.1: Threshold population inversionfor the He-Ne laser 181
4.7 Principle of the Laser Diode 181
4.8 Heterostructure Laser Diodes 185
Example 4.8.1: Modes in a laser and the optical cavity length 189
4.9 Elementary Laser Diode Characteristics 190
Example 4.9.1: Laser output wavelength variations 192
4.10 Steady State Semiconductor Rate Equation 192
4.11 Light Emitters for Optical Fiber Communications 195
4.12 Single Frequency Solid State Lasers 196
Example 4.12.1: DFB Laser 198
4.13 Quantum Well Devices 199
Example 4.13.1:A GaAs quantum well 202
4.14 Veical Cavity Surface Emitting Lasers (VCSELs) 203
4.15 Optical Laser Amplifiers 205
4.16 Holography 206
Questions and Problems 209
5. PHOTODETECTORS 217
5.1 Principle of the pn Junction Photodiode 217
5.2 Ramos Theorem and External Photocurrent 219
5.3 Absorption Coefficient and Photodiode Materials 221
5.4 Quantum Efficiency and Responsivity 224
5.5 The pin Photodiode 225
Example 5.5.1: Operation and speed of a pin photodiode 228
Example 5.5.2: Photocarrier diffusion in a pin photodiode 228
Example 5.5.3: Responsivity of a pin photodiode 229
5.6 Avalanche Photodiode 230
Example 5.6.1: InGaAs APD Responsivity 234
Example 5.6.2: Silicon APD 234
5.7 Heterojunction Photodiodes 234
A. Separate Absorption and Multiplication (SAM) APD 234
B. Superlattice APDs 2365.8 Phototransistors 237
5.9 Photoconductive Detectors and Photoconductive Gain 239
5.10 Noise In Photodetectors 242
A. The pn Junction and the pin Photodiodes 242
Example 5.10.1: NEP of a Si pin photodiode 244
Example 5.10.2: Noise of an ideal photodetector 244
Example 5.10.3: SNR of a receiver 245
B. Avalanche Noise in the APD 246
Example 5.10.4: Noise in an APD246Questions and Problems 247
6. PHOTOVOLTAIC DEVICES 254
6.1 Solar Energy Spectrum 254
Example 6.1.1: Solar energy conversion 256
6.2 Photovoltaic Device Principles 257
Example 6.2.1: The photocurrent Iph 260
6.3 pn Junction Photovoltaic I-V Characteristics 261
Example 6.3.1:A solar cell driving a resistive load 264
Example 6.3.2: Open circuit voltage and illumination 264
6.4 Series Resistance and Equivalent Circuit 265
Example 6.4.1: Solar cells in parallel 267
6.5 Temperature Effects 268
6.6 Solar Cells Materials, Devices, and Efficiencies 269
Questions and Problems 272
7. POLARIZATION AND MODULATION OF LIGHT 275
7.1 Polarization 275
A. State of Polarization 275
Example 7.1.1: Elliptical and circular polarization 278
B. Maluss Law 279
7.2 Light Propagation in an Anisotropic Medium: Birefringence 280
A. Optical Anisotropy 280
B. Uniaxial Crystals and Fresnels Optical Indicatrix 281
C. Birefringence of Calcite 285
D. Dichroism 286
7.3 Birefringent Optical Devices 287
A. Retarding Plates 287
Example 7.3.1: Quartz half-wave plate 288
Example 7.3.2: Circular polarization from linear polarization 289
B. Soleil-Babinet Compensator 289
C. Birefringent Prisms 291
7.4 Optical Activity and Circular Birefringence 292
7.5 Electro-Optic Effects 294
A. Definitions 294
B. Pockels Effect 295
Example 7.5.1: Pockels Cell Modulator 299
C. Kerr Effect 300
Example 7.5.2: Kerr effect modulator 301
7.6 Integrated Optical Modulators 301
A. Phase and Polarization Modulation 301
B. Mach-Zehnder Modulator 303
C. Coupled Waveguide Modulators 304
Example 7.6.1: Modulated directional coupler 307
7.7 Acousto-Optic Modulator 307
Example 7.7.1: Modulated Directional Coupler 309
7.8 Magneto-Optic Effects 310
7.9 Non-Linear Optics and Second Harmonic Generation 311
Questions and Problems 314
NOTATION AND ABBREVIATIONS 323
INDEX 332