Abstract

Spatial light modulators are essential (and often the limiting) elements in optical information processing and computing system architectures. Recent advances have demonstrated that optical memory disk technology, in combination with image-based recording and an appropriate parallel readout scheme of the high-resolution optical disk medium, presents a very competitive alternative for spatial light modulation.¹, ² Not only can this technology perform a wide variety of traditional spatial light modulator (SLM) functions, but it also makes implementation of multilayered neural networks and ultrahigh-data-rate scrolling input transducers possible by using the rotational motion characteristic of the optical-disk driver. A parallel optical-readout scheme that has an inherently high signal-to-noise-ratio, has high transfer function linearity, and can be used with a variety of recording layer principles can be achieved by employing a differential (or shearing) interferometric approach.¹ In this readout scheme, two spatially coherent orthogonally polarized images of the optical disk are created and are interfered differentially by introducing a shift of one-half of the minimum bit pitch along the direction of the tracks. In the output image, only local differences in phase (height) and/or reflectivity of the recording layer will be detected.

© 1990 Optical Society of America