Abstract

A cascadable shuffle-exchange network is proposed that couples the optical folded perfect shuffle (FPS) concept¹ with modulator-based exchange/bypass switches and avoids the need for optical signal regeneration at each stage. The network is based on the optically efficient version of the FPS.² For switching, the two-dimensional array of signals is processed pairwise. Each signal passes through a polarization-switching SLM pixel; rotated polarization corresponds to the "exchange" condition for a pair of signals. Exchanged pairs are routed, via a polarizing beam splitter, to an optical arm that uses imaging lenslet arrays to perform the pairwise exchange operation by inversion of the spatial locations of the elements of the pair. These signals are then recombined with those in the "bypass" arm, via another polarizing beam splitter, and the shuffled and exchanged signals are ready for input into a subsequent stage. Each of the cascaded modules in a multistage network would be identical and potentially made from inexpensive, replicated optics.

© 1990 Optical Society of America