Highly efficient holographic lens arrays for optical interconnect applications

Abstract

Many problems and limitations are foreseen in the near future of VLSI electronic circuit design. Perhaps one of the more important limitations is the interconnection between chips. The interconnects in use today are limited by space, speed, and interference effects. Optical interconnects have been offered as a solution to this limitation. Optical interconnects are not subject to propagation delays, loading effects, and interference effects that limit fan-out. The idea presented here is based on the use of a holographic optical element (HOE) as the optical interconnection between different devices. The HOE provides more freedom in designing the network as well as a means for reprogramming the interconnections. Several constraints are placed on the HOE. It must be highly efficient to ensure the best use of available power as well as to reduce optical noise in the system. A new photopolymer developed by Polaroid has the potential of providing the high efficiency needed for the HOE. Previously published results as well as preliminary investigations into the production of HOEs have been extremely encouraging. Small holographic lens arrays produced in the photopolymer currently exhibit high-diffraction efficiency.