Advances in optical technologies have made it possible to implement optical interconnections in future massively parallel processing systems. Photons are non-charged particles, and do not naturally interact. Consequently, there are many desirable characteristics of optical interconnects, e.g. high speed (speed of light), increased fanout, high bandwidth, high reliability, longer interconnection lengths, low power requirements, and immunity to EMI with reduced crosstalk. Optics can utilize free-space interconnects as well as guided wave technology, neither of which has the problems of VLSI technology mentioned above. Optical interconnections can be built at various levels, providing chip-to-chip, module-to-module, board-to-board, and node-to-node communications. Massively parallel processing using optical interconnections poses new challenges; new system configurations need to be designed, scheduling and data communication schemes based on new resource metrics need to be investigated, algorithms for a wide variety of applications need to be developed under the novel computation models that optical interconnections permit, and so on. Parallel Computing Using Optical Interconnections is a collection of survey articles written by leading and active scientists in the area of parallel computing using optical interconnections. This is the first book which provides current and comprehensive coverage of the field, reflects the state of the art from high-level architecture design and algorithmic points of view, and points out directions for further research and development.

Optical media are now widely used in the telecommunication networks, and the evolution of optical and optoelectronic technologies tends to show that their wide range of techniques could be successfully introduced in shorter-distance interconnection systems. This book bridges the existing gap between research in optical interconnects and research in high-performance computing and communication systems, of which parallel processing is just an example. It also provides a more comprehensive understanding of the advantages and limitations of optics as applied to high-speed communications. Audience: The book will be a vital resource for researchers and graduate students of optical interconnects, computer architectures and high-performance computing and communication systems who wish to understand the trends in the newest technologies, models and communication issues in the field.

This text covers the subjects of computer architecture and parallel and high-performance computing. Topics include: free-space optical interconnect systems; design and analysis of optical interconnects; interconnect system analysis; and fiber-based interconnects.

This volume is a monograph on parallel optical interconnects. It presents not only the state of-the-art in this domain but also the necessary physical and chemical background. It also provides a discussion of the potential for future devices. Both experts and newcomers to the area will appreciate the authors' proficiency in providing the complete picture of this rapidly growing field. Optical interconnects are already established in telecommunications and should eventually find their way being applied to chip and even gate level connections in integrated systems. The inspiring environment of the Basic Research Working Group on Optical Information Technology WOIT (3199), together with the excellent and complementary skills of its participants, make this contribution highly worthwhile. G. Metakides Table of contents 1 Perspectives for parallel optical interconnects: introduction . . . . . . . . . . . . . . . . . . . . . . . . . l Pierre Chavel and Philippe lAlanne 1. 1 Optical Interconnects and ESPRIT BRA WOIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 2 What are optical interconnects? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1. 3 Optical interconnects: how ? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 3. 1 Passive devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 3. 2 Active devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 3. 3 Schemes for parallel optical interconnects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 3. 4 Limits of optical interconnects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 4 Optical interconnects: why ? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Acknowledgetnents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 First Section: Components Part 1. 1 Passive interconnect components 2 Free space interconnects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Philippe Lalanne and Pierre ChaveZ 2. 1 Introduction: 3D optical interconnects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 2 Optical free space channels and their implementations . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. 2. 1 Diffraction and degrees of freedom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. 2. 2 Two Qasic interconnect setups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .