Abstract

The color-blurred correlation term of a white-light optical processor is calculated and characterized by its autocorrelation spot size, peak intensity, and energy efficiency. The spatial frequency of the input plane diffraction grating and the bandwidth of the filter in the Fourier transform plane are the primary design parameters. In addition, lateral chromatic aberration corrections are included. Increasing the spatial frequency of the input grating yields a spot with a reduced chromatic blur along the y axis while maintaining an accurate correlation measurement along the x axis. Correcting the lateral chromatic dispersion of the transform plane diffraction encoding further reduces the blur along the y axis but also creates chromatic blur along the x axis. The performance of the processor is assessed for alphanumeric character recognition, and its operation is summarized by an analytically calculated model. Certian classes of input patterns are shown to have minimum correlation spot blurring.

© 1985 Optical Society of America