|Publication No: 245P||Search all ORC publications|
Velocity filtering using complementary gratings in photorefractive BSO
Dept. of Physics and Optoelectronics Research Centre, University of Southampton, UK
We demonstrate a new optical technique for velocity filtering and feature extraction of time varying optical images. The technique exploits the recording of complementary (multiplexed) gratings with a relative phase shift of 180° in a photorefractive material, BSO, via a degenerate four wave mixing (DFWM ) configuration. For experimental parameters, such as grating response time and optimised total input intensity. almost complete subtraction is achieved in the phase conjugate output. When motion occurs in the object plane a bright output image is observed depending on the experimental variables of feature size and velocity. We present results for motion detection of features of various dimensions at a range of speeds in both x and y directions and via Fourier plane observation.
Optics Communications (1991) Vol.86(2) pp.106-112
Copyright University of Southampton 2006