Optical correlators with fast updating speed using photorefractive semicondutor materials

Abstract

An updatable optical correlator which uses a photorefractive compound semiconductor to generate real-time matched filters is proposed. Using compound semiconductors offers high speed with low optical input intensities. Here we discuss issues affecting the performance of this correlator. This includes an analysis of the Bragg diffraction and a discussion of the speed and power considerations of these materials. Experimental results obtained using photorefractive GaAs are also presented.

Particle-Imaging Techniques for Experimental Fluid Mechanics

“…Coupland & Halliwell (1988) report 1 s response at 10 mW cm -2. However, Gheen & Cheng (1988) have demonstrated 1000 times faster response in GaAs:Cr photorefractive compound semiconductors. Another approach to optical correlation uses a video camera to digitize the intensity of the Young's fringe pattern and then writes the intensity pattern to a medium whose amplitude transmittance is proportional to the write signal.…”

<title>Holography in biosciences</title>

“…Applications on holographic matched filtering [31][32][33], holographic interferometry [34] and moire holography [15] have been described in the literature.…”

<title>Specially doped (Ce:Fe:) LiNbO<formula><inf><roman>3</roman></inf></formula>-based crystal holography</title>

“…In recent years, applications of photorefractive (PR) crystal to optical interconnections [1], optical signal processing [2], novelty filters [3], as well as storage [4], have been widely advocated. However, one of the major impediments that prevents the wide spread of application must be the high power requirement for the PR crystals.…”