Three - dimensional Optical Interconnects for High - density Chip - to - chip and Board -

It is generally accepted that the most basic obstacle to continued advances in the speed of computing systems is metal connections. The bottleneck of current metal-based interconnection networks is typically the very limited bandwidth. Optics, due to its inherent parallelism, high bandwidth, freedom from planar constraints, and non-interfering communication, has been recognized as a possible solution to the communication problem in high-performance computing systems. In this paper, we propose a model of 3-D free-space optical interconnection network architectures for chip-to-chip and board-to-board communications. The model is intended to provide high enough communication bandwidth as well as parallelism required by massively parallel computing systems. In the model, inter-processor links are provided by free-space optics eliminating all electrical links between processors, which results in denser realization of processor arrays as well as higher interconnect densities than electrical approaches. We also show how to embed the binary n-cube and the mesh networks into the model.