Abstract

We report the development of a demonstration optical interconnect module for VLSI using holograms and liquid crystal switches. The objective was a global switching module. The design is a solid optical system using compact liquid crystal polarizing switches integrated in a packed array of polarizing beam splitters which feed the individual holograms. The need is an N × N crossbar switch to reprogram efficient hardwired machines. However most of the possible interconnect patterns are thought to be unnecessary or essentially redundant in a highly parallel system and access to a small number of intelligently selected data patterns would approach the speed possible with an exhaustive crossbar switch. The holographic multiplexer can provide the needed set of complex data flow patterns, accomplishing updates with the addition of new holograms. The optical interconnect has N sources and N detectors giving a system complexity of order N. An electronic crossbar has N input and output lines but the number of switches grow as N-squared, which is expected to become a problem as N grows beyond 1000.

© 1986 Optical Society of America