Particle image velocimetry: high-speed transparency scanning and correlation-peak location in optical processing systems

Abstract

In order to exploit the full potential offered by optical correlation processing in the analysis of transparencies obtained by particle image velocimetry one needs to advance the transparency and to track the position of correlation peaks at great speed. In the following, this procedure is discussed with reference to an optical analysis system based on a high-speed ferroelectric optically addressed spatial light modulator. We present a system that uses scanning optics both to scan through the input transparency and to locate the correlation peaks in the resulting optical output distributions as a practical solution to the problem. The feasibility of this approach is demonstrated at a processing speed of ~500 autocorrelations/s when a one-dimensional acousto-optic output scanning device is used.