Silicon Photonics

M. Jamal Deen completed a BSc degree at the University of Guyana (Guyana) and a PhD in Electrical Engineering and Applied Physics at Case Western Reserve University (USA). Professor Deen has been an assistant professor at Lehigh University, Bethlehem (USA) and was professor in the School of Engineering Science, Simon Fraser University, Vancouver (Canada). In 1999, he assumed his current position as Professor of Electrical and Computer Engineering, McMaster University, Hamilton (Canada). His current research interests include physics, modeling, reliability and parameter extraction of semiconductor devices; optical detectors and receivers, polymers and organic semiconductor devices, and low power, low-noise, high-frequency circuits. He is a Distinguished Lecturer of the IEEE- Electron Device Society, was awarded the 2002 Thomas D. Callinan Award from the Electrochemical Society, the Distinguished Researcher award, Province of Ontario and a Humboldt Research Award from the Alexander von Humboldt Foundation in 2006. In September 2008, he was awarded the prestigious Thomas W. Eadie medal by the Royal Society of Canada for his work on the modeling and noise of electronic and optoelectronic devices, with particular reference to silicon transistors and high-speed photodetectors.Prasanta Kumar Basu obtained his BSc and his PhD from the University of Calcutta (India). He worked in the Institute of Radio Physics and Electronics, as a lecturer, then as a reader and finally as a professor. He served as the Head of the Department and he is now the Programme Coordinator of the Centre of Advanced Study in Radio Physics and Electronics at the University of Calcutta. Professor Basu worked as a Postdoctoral Fellow at the Catholic University, Leuven, Belgium, as an Alexander von Humboldt Fellow in Wuerzburg University, Germany and has been a visiting professor at McMaster University, Hamilton, Canada several times. Professor Basu’s research interests include semiconductor physics and devices, optoelectronics and optical communication, nanoelectronics and nanophotonics. He has more than 100 research publications in refereed journals and has authored a book Theory of Optical Processes in Semiconductors: Bulk and Microstructures.

• Series Preface xv Preface xvii1 Introduction to Silicon Photonics 11.1 Introduction 11.2 VLSI: Past, Present, and Future Roadmap 21.3 The Interconnect Problem in VLSI 31.4 The Long-Haul Optical Communication Link 41.5 Data Network 71.6 Conclusions 71.7 Scope of the Book 82 Basic Properties of Silicon 112.1 Introduction 112.2 Band Structure 122.3 Density-of-States Function 172.4 Impurities 192.5 Alloys of Silicon and Other Group IV Elements 212.6 Heterojunctions and Band Lineup 232.7 Si-Based Heterostructures 242.8 Direct GAP: Ge/SiGeSn Heterojunctions 333 Quantum Structures 413.1 Introduction 413.2 Quantum Wells 413.3 Quantum Wires and Dots 483.4 Superlattices 503.5 Si-Based Quantum Structures 523.6 Effect of Electric Field 564 Optical Processes 614.1 Introduction 614.2 Optical Constants 614.3 Basic Concepts 644.4 Absorption Processes in Semiconductors 664.5 Fundamental Absorption in Direct GAP 664.6 Fundamental Absorption in Indirect GAP 734.7 Absorption and Gain 774.8 Intervalence Band Absorption 794.9 Free-carrier Absorption 804.10 Recombination and Luminescence 824.11 Nonradiative Recombination 864.12 Excitonic and Impurity Absorption 915 Optical Processes in Quantum Structures 975.1 Introduction 975.2 Optical Processes in QWs 985.3 Intersubband Transitions 1055.4 Excitonic Processes in QWs 1095.5 Effect of Electric Fields 1145.6 Optical Processes in QWRs 1185.7 Optical Processes in QDS 1196 Light Emitters in Si 1236.1 Introduction 1236.2 Basic Theory of Light Emission 1246.3 Early Efforts: Zone Folding 1256.4 Band Structure Engineering Using Alloys 1266.5 Quantum Confinement 1296.6 Imputities in Silicon 1346.7 Stimulated Emission: Prospect 1396.8 Intersubband Emission 1436.9 Tensile-Strained Ge Layers 1467 Si Light Modulators 1517.1 Introduction 1517.2 Physical Effects 1527.3 Electrorefraction in Silicon 1567.4 Thermo-Optic Effects in Si 1587.5 Modulators: Some Useful Characteristics 1597.6 Modulation Bandwidth under Injection 1607.7 Optical Structures 1617.8 Electrical Structures 1647.9 High-Bandwidth Modulators 1687.10 Performance of EO Modulators 1708 Silicon Photodetectors 1758.1 Introduction 1758.2 Optical Detection 1768.3 Important Characteristics of Photodetectors 1808.4 Examples of Types of Photodetectors 1878.5 Examples of Photodiodes in Standard Silicon Technology 1928.6 Phototransistors in Standard Silicon Technology 1968.7 CMOS and BiCMOS 1978.8 Silicon-on-Insulator (SOI) 1988.9 Photodetectors Using Heteroepitaxy 2029 Raman Lasers 2199.1 Introduction 2199.2 Raman Scattering: Basic Concepts 2209.3 Simplified Theory of Raman Scattering 2229.4 Raman Effect in Silicon 2249.5 Raman Gain Coefficient 2249.6 Continuous-Wave Raman Laser 2289.7 Further Developments 23010 Guided Lightwaves: Introduction 23310.1 Introduction 23310.2 Ray Optic Theory for Light Guidance 23310.3 Reflection Coefficients 23410.4 Modes of a Planar Waveguide 23510.5 Wave Theory of Light Guides 23810.6 3D Optical Waveguides 24410.7 Loss Mechanisms in Waveguides 25210.8 Coupling to Optical Devices 25710.9 Tapers 26111 Principle of Planar Waveguide Devices 26711.1 Introduction 26711.2 Model for Mode Coupling 26711.3 Directional Coupler 27011.4 Distributed Bragg Reflector 27311.5 Some Useful Planar Devices 27712 Waveguides for Dense Wavelength-Division Multiplexing (DWDM) Systems 29312.1 Introduction 29312.2 Structure and Operation of AWGs 29412.3 AWG Characteristics 29712.4 Methods for Improving Performance 30012.5 Applications of AWGs 30312.6 PHASAR-Based Devices on Different Materials 30612.7 Echelle Grating 30713 Fabrication Techniques and Materials Systems 31113.1 Introduction 31113.2 Planar Processing 31213.3 Substrate Growth and Preparation 31213.4 Material Modification 31813.5 Etching 32213.6 Lithography 32613.7 Fabrication of Waveguides 32813.8 Grating Formation Process 33113.9 Materials Systems for Waveguide Formation 334Problems 348References 349Further Reading 352Appendix A: k.p Method 355Appendix B: Values of Parameters 371Index