AbstractA joint transform correlator (JTC) using photorefractive Bismuth Silicon Oxide (BSO) as a nonlinear recording medium, and a liquid crystal television (LCTV) as a spatial light modulator (SLM) is implemented. The physical basis of the processes involved in the photoreffactive recording is studied, and the moving grating enhancement technique is investigated.
Photoreffactive BSO is investigated for use as the holographic recording medium in information processing systems. The moving grating technique is investigated as a means of enhancing the photoreffactive effect and therefore improving correlation performance. The nonlinear effects of moving gratings at high fringe modulations for two-wave mixing experiments are investigated and compared with numerical predictions. The effect of moving gratings on phase conjugate reflectivity via four-wave mixing is also studied experimentally.
The photoreffactive joint transform correlator makes use of an LCTV as an SLM. The operation of an inexpensive LCTV is studied, and the optimum working conditions for the present application are determined.
The principles behind optical correlation are developed and the consequences of using photoreffactive BSO as the recording medium are discussed. A technique for encoding information in the object plane to yield phase-only information in the Fourier plane is presented. This technique is applied to the photoreffactive joint transform correlator and the performance is studied. Computational models of the correlator are presented, and the theoretical performance is compared with experimental results.
|Date of Award||Mar 1998|
|Supervisor||Colin Cartwright (Supervisor) & Allan Gillespie (Supervisor)|