Abstract

Functions of two independent variables are often produced by manipulating, e.g., correlating, data fields or sequences. Two commonly encountered examples are the ambiguity function and the Wigner distribution. The amplitudes of such functions may be generated and displayed optically in a 2-D format. Extracting features from this format (e.g., peaks produced by preceding threshold or hard-clip operations) is a time-consuming task when attempted by serial access. Various optical encoding schemes can multiplex the pixel addresses of peak features into a number of parallel outputs or even into a single sequential signal. The nonlinear processing which generates and displays the pixels of interest is accomplished using a 2-D spatial light modulator. Light from these pixels is multiplied row by row by sets of orthogonal codes using an acoustooptic Bragg cell or a fixed mask along with appropriate anamorphic optics. Rows are then summed on a detector array to perform the multiplexing. Subsequent matched filtering of the detector array output identifies the active spatial light modulator sites.

© 1987 Optical Society of America