Optical Interconnection Architectures for High-Performance Computers and Switches

Doctoral thesis, 2003

The incredible growth in processing power and switching capacity in high-performance computers and switches puts very high demands on the interconnection networks. This is recognized in particular in massively parallel processing and extreme switching architectures. The demands are such that new interconnection architectures must be considered. In this thesis, we give close consideration to the characteristics of both optics and electronics in order to find new interconnection architectures. We also explore how optical interconnections can provide a new design space for developers of parallel computer systems. We believe that planar integrated free-space optics technology is a strong candidate for implementing the kind of interconnection networks considered necessary for the applications studied in this thesis. We therefore base our work on new interconnection architectures on this technology. Our approach is to try to fit algorithms, architectures and physical implementations to each other to offer systems with high performance. The thesis gives important input in the form of examples to show the advantages of using optical interconnections in the designs of future high-performance embedded signal processing systems and switches and routers. We show how the use of free-space optical interconnections makes it possible to implement heavily cross-connected and complicated network topologies suitable for embedded signal processing. We also demonstrate that totally different switch fabric architectures can make use of optical technologies to facilitate the design of deeply cross-connected high capacity switches. The results show that several expected requirements of future embedded signal processing systems and terabit switches and routers can be met using optical solutions over short distances, e.g. the chip-to-chip or board-to-board level.