Real-time nonlinear optical correlator in speckle metrology

摘要

In speckle correlation technique, both the specklegram and its Fourier transformed fringe pattern are detected by nonlinear Optic RAM detectors. The speckle correlation is calculated by the nonlinear optical correlator using a phase modulation property of a liquid crystal television. The effects of the binarization for the signals on the diffraction efficiency are discussed theoretically and experimentally.