Recent results of a phase-conjugate holographic system for high-resolution particle image holography

A novel holographic particle image velocimeter system has been developed for the study of three-dimensional fluid velocity fields. The recording system produces three-dimensional particle images of micron-sized particles with a resolution, signal-to-noise ratio, accuracy and derived velocity fields that are comparable to high-quality two-dimensional photographic PIV (particle image velocimetry). The high image resolution is accomplished by using low f- number optics, a fringe stabilized processing chemistry, and a phase conjugate play-back geometry that compensates for aberrations in the imaging system. In addition, the system employs a reference multiplexed, off-axis geometry for determining velocity directions using the cross-correlation technique, and a stereo camera geometry for determining the three velocity components. The combination of the imaging and reconstruction sub-systems make the analysis of volumetric PIV domains feasible. Recent results using the newly developed HPIV system are presented and potential uses of the system in other holographic imaging applications are discussed as well.