Guided Wave Optoelectronics

1. Introduction..- 1.1 Overview.- 1.2 Organization of the Book.- References.- 2. Theory of Optical Waveguides. (With 32 Figures).- 2.1 Ray Optics of the Slab Waveguide.- 2.1.1 Refraction and Reflection.- 2.1.2 Guided Modes.- 2.1.3 The Goos-Hanchen Shift.- 2.1.4 Effective Guide Thickness.- 2.2 Fundamentals of the Electromagnetic Theory of Dielectric Waveguides.- 2.2.1 Maxwell's Equations.- 2.2.2 Modes of the Waveguide.- 2.2.3 The Wave Equations for Planar Guides.- 2.2.4 Mode Properties Following from Symmetry.- 2.2.5 Orthogonality of the Modes.- 2.2.6 Mode Expansion and Normalization.- 2.2.7 The Variation Theorem for Dielectric Waveguides.- 2.2.8 Power Flow and Stored Energy in a Dielectric Waveguide.- 2.2.9 Variational Properties of the Propagation Constant.- 2.3 Modes of the Planar Slab Guide.- 2.3.1 TE Modes.- 2.3.2 TM Modes.- 2.3.3 Multilayer Slab Guides.- 2.4 Planar Guides with Graded-Index Profiles.- 2.4.1 The Parabolic Profile (Harmonic Oscillator).- 2.4.2 The "1/cosh2" Profile.- 2.4.3 The Exponential Profile.- 2.4.4 Index Profiles with Strong Asymmetry.- 2.4.5 The WKB Method.- 2.5 Channel Waveguides.- 2.5.1 Channel Guide Geometries.- 2.5.2 The Vector Wave Equation.- 2.5.3 Numerical Analysis.- 2.5.4 Separation of Variables.- 2.5.5 The Method of Field Shadows.- 2.5.6 The Vector Perturbation Theorem.- 2.5.7 The Effective-Index Method.- 2.6 Coupled-Mode Formalism and Periodic Waveguides.- 2.6.1 Excitation of Waveguide Modes.- 2.6.2 Waveguide Deformations.- 2.6.3 Coupled-Wave Solutions.- 2.6.4 Periodic Waveguides.- 2.6.5 TE-to-TM Mode Conversion.- References.- 3. Waveguide Transitions and Junctions (With 43 Figures).- 3.1 Waveguide Modes and Coupled-Mode Theory.- 3.1.1 Normal Modes of Coupled Waveguides.- 3.1.2 Coupled-Mode Theory Representation.- 3.2 Fast and Slow Transitions.- 3.2.1 Local Normal Modes.- 3.2.2 Adiabatic Transition.- 3.2.3 Abrupt Transition.- 3.2.4 Tapered Velocity Coupler.- 3.2.5 3 dB Coupler.- 3.2.6 Directional Coupler.- 3.3 Mode Coupling Between Local Normal Modes.- 3.3.1 Coupled-Amplitude Equations.- 3.3.2 Differential Form of Coupled-Amplitude Equations.- 3.3.3 Coupled-Mode Theory Representation of Cij.- 3.4 Two-Arm Branches.- 3.4.1 Step Approximation for a Waveguide Branch.- 3.4.2 Analytic Solution for Shaped Branches.- 3.4.3 Experimental Results.- 3.4.4 Superposition of Solutions.- 3.5 Waveguide Horns.- 3.5.1 Mode-Conversion Coefficient Cij for Channel Waveguides.- 3.5.2 Approximation for ??ij.- 3.5.3 Approximation for Cij.- 3.5.4 Parabolic Solution.- 3.6 Branches with Three Arms.- 3.6.1 Normal Modes of Three Coupled Waveguides.- 3.6.2 3 X 2 Waveguide Coupler.- 3.7 Conclusion.- References.- 4. Titanium-Diffused Lithium Niobate Waveguide Devices (With 39 Figures).- 4.1 Waveguide Fabrication.- 4.1.1 Titanium Diffused Waveguides.- 4.1.2 Proton Exchange LiNbO3 Waveguides.- 4.1.3 Post-Waveguide Processing.- 4.2 Basic Device Considerations.- 4.2.1 Electro-Optic Effect.- 4.2.2 Phase Modulator.- 4.2.3 Insertion Loss.- 4.2.4 Voltage/Loss Tradeoffs: Waveguide Tailoring.- 4.3 Switch/Modulator.- 4.3.1 Directional Coupler.- 4.3.2 Balanced-Bridge Interferometer.- 4.3.3 Intersecting-Waveguide Switch.- 4.4 On/Off Modulators.- 4.4.1 Y-Branch Interferometer.- 4.4.2 Voltage and Bandwidth Consideration for Switch/ Modulators.- 4.5 Polarization Devices.- 4.5.1 TE - TM Conversion.- 4.5.2 Polarization Controller.- 4.5.3 Polarization-Selective Devices.- 4.6 Wavelength Filters.- 4.6.1 Interferometric Filters.- 4.6.2 Coupled-Mode Filters.- 4.7 Polarization-Insensitive Devices.- 4.8 Some Ti:LiNbO3 Integrated-Optic Circuits.- 4.8.1 Coherent Lightwave Receiver.- 4.8.2 Optical Switch Arrays.- 4.9 Applications.- 4.9.1 External Modulators.- 4.9.2 High-Speed Analog to Digital Conversion.- 4.9.3 Fiber Gyroscope Chip.- References.- 5. Mode-Controlled Semiconductor Lasers (With 55 Figures).- 5.1 Organization of the Chapter.- 5.1.1 Notation.- 5.2 Laser Basics.- 5.2.1 Epitaxial Materials and Heterostructure.- 5.2.2 Waveguide Propagation, Amplification and Oscillation.- 5.2.3 Laser Gain.- 5.2.4 Spontaneous Emission.- 5.2.5 Photon Rate Equation.- 5.2.6 Spectral Hole Burning.- 5.2.7 Carrier Injection in a Heterojunction.- 5.2.8 Modal Rate Equations.- 5.2.9 Longitudinal Variation of Photon Density.- 5.2.10 Steady-State Solution of Rate Equations.- 5.2.11 Measurement of Modal Reflectivity and Laser Gain.- 5.3 Structures for Transverse-Mode Control.- 5.3.1 Stripe Geometry Laser, Blocking Layer.- 5.3.2 Buried Heterostructure Lasers.- 5.3.3 Ridge Waveguide Lasers.- 5.4 Longitudinal Mode Control.- 5.4.1 Three- and Four-Mirror Resonators.- 5.4.2 Distributed Bragg Gratings.- 5.4.3 Semiconductor DFB Lasers.- 5.4.4 DBR and Phase-Slip DFB Lasers.- 5.5 Linewidth.- 5.5.1 Linewidth of Fabry-Perot Laser.- 5.5.2 Linewidth Reduction Using Extended Cavities.- 5.6 High-Speed Modulation.- 5.6.1 Modulation Response.- 5.6.2 Origin of Chip Parasitics.- 5.6.3 Evaluation of Parasitics.- 5.6.4 Dependence of Parasitics on Device Structure.- 5.6.5 The Intrinsic Laser - Small-Signal Intensity Modulation Response.- 5.6.6 High-Frequency Limitations.- 5.6.7 Design Considerations for Wideband Lasers.- 5.6.8 Large-Signal Modulation - PCM.- 5.6.9 Large-Signal Modulation - Gain Switching.- 5.6.10 Active Mode-Locking.- 5.7 Luminescent Diodes and Laser Amplifiers.- 5.7.1 Edge-Emitting and Superluminescent Diodes.- 5.7.2 Linear Amplification and Amplified Spontaneous Emission in TWAs and ELEDs.- 5.7.3 Fabry-Perot Amplifiers and ELEDs.- 5.7.4 Amplifier Gain Compression.- 5.7.5 Receiver Noise.- 5.8 Tunable and FM Lasers.- 5.8.1 Tunable DBR.- 5.8.2 Tunable DFB.- Appendix 5A: Glossary of Symbols.- References.- 6. Semiconductor Integrated Optic Devices (With 66 Figures).- 6.1 Semiconductor Waveguide Theory.- 6.1.1 Methods of Index Change in Semiconductors.- 6.1.2 Slab Waveguides.- 6.1.3 Channel Waveguides.- 6.1.4 Coupling Effects.- 6.1.5 Optical Loss.- 6.1.6 Curvature Loss.- 6.2 Material Technology.- 6.2.1 Liquid Phase Epitaxy (LPE).- 6.2.2 Vapor Phase Epitaxy (VPE).- 6.2.3 Metal Organic Chemical Vapor Deposition (MOCVD).- 6.2.4 Molecular Beam Epitaxy (MBE).- 6.2.5 Summary.- 6.3 Passive Waveguide Devices - Fabrication and Characterization.- 6.3.1 Channel Waveguides.- 6.3.2 Couplers.- 6.3.3 Bends and Branches.- 6.3.4 Grating Filter.- 6.4 Electro-Optic Guided-Wave Modulators - Theory.- 6.4.1 Electro-Optic Effect in III-V Semiconductors.- 6.4.2 Modulator Design.- 6.4.3 Modulation Frequency Analysis.- 6.4.4 Traveling-Wave Phase Modulators.- 6.4.5 TE-TM Coupling Analysis.- 6.4.6 Infrared Waveguide Modulators - Wavelength Scaling.- 6.4.7 Electro-Absorption Modulation.- 6.4.8 Carrier-Injection Modulator.- 6.4.9 Nonlinear Waveguide Modulator.- 6.5 Electro-Optic Guided-Wave Modulator Characteristics.- 6.5.1 Phase Modulators.- 6.5.2 Directional-Coupler Switches.- 6.5.3 Interferometric Modulators.- 6.5.4 Integrated Waveguides/Optoelectronics/Electronics.- 6.5.5 Electro-Absorption Modulators.- 6.5.6 Multiple-Quant urn-Well Modulators.- 6.5.7 Nonlinear Waveguide Modulators.- 6.6 Optoelectronic Integrated Circuits (OEIC).- 6.7 Concluding Remarks.- References.- 7. Recent Advances (With 1 Figure).- 7.1 Introduction.- 7.2 Theory of Optical Waveguides.- 7.3 Waveguide Transitions and Junctions.- 7.4 Titanium-Diffused Lithium Niobate Waveguide Devices.- 7.5 Mode-Controlled Semiconductor Lasers.- 7.6 Semiconductor Integrated Optic Devices.- References.