Optimization of parameters in matched spatial filter synthesis

The three major parameters that must be selected in matched spatial filter (MSF) synthesis are the bias exposure for the MSF, the beam balance ratio (ratio of the intensity of the reference and signal beams), and the spatial frequency band in which this ratio is set. In the present paper, the influence of these parameters in MSF synthesis in achieving the largest peak intensity and SNR of an output correlation is studied theoretically and experimentally. The optical system used is described, along with the MSF synthesis and correlation process. Reliable data for assessing the influence of the MSF synthesis parameters under consideration were obtained with the aid of a diffraction pattern sampling unit in the Fourier transform plane. Criteria for selecting the MSF synthesis parameters are proposed, and the need to specify the spatial frequency band at which the beam balance ratio is set is demonstrated.