A complexity analysis of optically implemented shuffle equivalent interconnection topologies based on computer generated binary phase gratings

Abstract

Free-space digital optics (FSDO) is an evolving interconnection technology that may permit signals to be routed between digital integrated circuit chips as beams of light propagating orthogonal to the plane of the device substrates. In switching systems, FSDO can be used to provide high-density, high-bandwidth, low-energy, low-noise connections between the nodes in multi-stage interconnection networks (MINs).[1] In this paper, various MIN architectures are examined and compared to determine the complexity and feasibility of their associated optical implementations. In particular, the paper explores efficient means of implementing two well-known interconnection topologies (the 2-banyan and the 4-shuffle ) and two novel interconnection topologies (the segmented-2-shuffle and the 4-banyan) using computer generated, space-invariant binary phase gratings. The paper also studies the effects of node-type and interconnection topology on the laser power requirements and the optical component requirements within the system. The general class of networks known as Extended Generalized Shuffle (EGS) networks will be used as a baseline for the analysis. The results should help identify optimum architectural parameters (node-type and interconnection topology) given the constraints of FSDO technologies.