Characterization of the PROM for Coherent Optical Processing Applications.
Abstract
The effort was divided into two primary tasks as follows: Task 1 - Image Plane Processing and Cross-Correlation-- Using a pair of stereo transparencies of a laboratory slope model, photographs of constant elevation fringes were obtained using 5 mw of HeNe laser for PROM readout. The technique was shown to be feasible and it was determined that significantly more readout illumination, such as 50 nw or more from the Krypton 647 nm line, would be required for a usable image reconstruction which displays the contours. Task 2 - Fourier Plane Filtering-- (a) PROM Filtering. Complex Vander Lugt filters were exposed on the PROM and film and reconstructed. A comparison of the PROM and film filters was discussed. (b) Pattern Generator/PROM. Various programmable filter patterns were written on the PROM and the characteristics of the Laser Raster Generator (LRG) were analyzed. A tradeoff study of LRG spot size versus scan overlap was performed. (c) Minicomputer PROM Filters. Versatile software for filter computation on the HP 2116C minicomputer was written, checked out, and demonstrated with the LRG and PROM. Software for fast disk readout to the LRG was also demonstrated. (d) Two-PROM System. The feasibility of real-time optical processing was demonstrated using two PROM devices. The first PROM was used in the input image plane as an incoherent-to-coherent converter and the second PROM was used as a laser addressed, programmable Fourier plane filter. Low-pass filtering, orientation selection, and spatial differentiation were demonstrated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 09, 1976
- Accession Number
- ADA030137
Entities
People
- J. Frattarola
- P. Nisenson
- S. Iwasa
- T. Sparks
- V. Bennett