Abstract

The use of the widely available photorefractive material, Bismuth Silicon Oxide (BSO), as a tunable holographic filter¹ is an extremely effective optical technique with which the performance of optical correlators² can be improved. This approach was physically implemented as part of a matched filter by Young and Chatwin³; it exploits selective erasure of spatial frequencies at the Fourier plane in the photorefractive material BSO. Experimental work^1,3 shows that the tuneable photo-refractive (TPR) filter not only gives sharp correlation peaks and good discrimination ability but is updateable and tuneable in real time via a variable attenuator, see Fig. 1.

© 1995 IEEE