Abstract

AT&T's photonics switching technology group has demonstrated a series of prototype systems of increasing complexity to test and illustrate the feasibility of free-space digital optical systems. Computer generated holograms (CGH) were incorporated into a multistage system demonstration (i) to distribute optical power and illuminate an array of optical processors,¹ and (ii) to form interconnections between stages. A 64 × 64 spot array was generated by illuminating a CGH with a collimated laser beam. The spot array intensity was required to vary by <20% between minimum and maximum intensity spots. A characterization system was used to ensure that this objective was met. To provide connectivity between channels, the information from each device was routed between modules using a scheme similar to a banyan network. By selectively shielding areas on the processor array, the interconnection was achieved using space invariant 1 × 3 CGHs. Some 1 × 3s were designed for reduced intensities at several higher-order spots.

© 1991 Optical Society of America