Abstract

An investigation into acoustooptic (AO) correlation and spectrum analysis using partially coherent light is presented. The salient feature of the processing architectures is the implementation of a white-light source to reduce coherent artifact noise at the detector plane. In all information processing operations the Bragg cell is amplitude modulated to perform linear processing of light in complex amplitude. Pure sinusoidal signals with no input noise were used to drive the AO cells to isolate the effects of the multiplicative phase noise. This phase noise arises from random thickness variations and refractive-index fluctuations. Two signal-to-noise ratio (SNR) measurements are used to compare partially coherent light and laser light for the same signal processing architectures. A theoretical treatment is given to quantify the effects of the spatial and temporal coherence on these SNR measurements. Finally, the effects of the temporal and spatial coherence on the correlation peak intensity for a space-integrating and a time-integrating architecture is described. Similarly these effects are studied in the spectral estimation peak for the spectrum analyzer.

© 1985 Optical Society of America