Abstract

The operation of 2-D Fourier tTransform has been the foundation of most of the coherent optical processors developed. Two prominent examples are the tilted-plane optical processor for SAR data and the Fourier plane image correlator/processor. In all of these cases the processing throughput of the system is limited by the space-bandwidth product and the frame-time of the input (spatial light modulators - SLMs) and output (detector arrays) transducers (typically 512 x 512 at 30 frames/s). The passive optical elements (e.g. lenses) are, however, capable of handling much larger size images (4000 × 4000). In this paper we describe a system design that uses several discrete SLMs and combines their outputs coherently to optically synthesize a much larger size image that can then be processed in parallel by the Fourier transform-based optical processor. The output (power spectrum or correlation) can be similarly split optical and detected by several separate detector arrays. We call this concept "Optical MOSAIC Processors" since it is similar to puting several individual tiles together to cover a large area. The combining of the subimages in the input and splitting them in the output can be accomplished using prisms/gratings and mirrors or via coherent fiber bundles. The randomization of the optical wavefront in the input can be corrected via a phase correcting hologram. In this paper we will describe several promising designs and outline potential applications.

© 1990 Optical Society of America