Abstract

Volume holograms stored in a photorefractive crystal can be used as routing templates for an optical communication switch.^1,2 The holograms are recorded by using reference beams that are spatially modulated with different intensity-modulated codes. When a communication channel's optical carrier is subsequently used as the read beam for the stored holograms, a spatial light modulator (SLM) applies the desired code to program the switch to deliver the signal to a particular detector. The diffraction efficiency, beam power, system bandwidth, and the detector noise determine the signal-to-noise ratio and hence the bit error rate (BER) at the detector. Furthermore, if the system is to multiplex multiple channels, the finite SLM contrast ratio will add crosstalk noise. If values for these system parameters are chosen, the minimum diffraction efficiency (hence the maximum number of holograms that can be stored in a l cm3 holographic recording medium) as a function of the SLM contrast ratio, the particular photodetector, and system bandwidth requirements are determined.

© 1990 Optical Society of America