Abstract

Acoustooptic devices have been used in a variety of applications, such as laser beam deflectors, modulators, tunable optical filters, and signal processors. This paper discusses an architecture for an acoustooptic correlator. Two parallel on-plane acoustooptic cells are employed to convert electrical signals into acoustic strain fields which modulate incident laser light. The Fourier transforms of the acoustic fields are produced with a lens on the input plane of a liquid crystal light valve. The inverse Fourier transform of the readout beam of the liquid crystal light valve provides the cross-correlation of two input signals. Since two acoustooptic cells are in the same plane, the proposed architecture can be minimized and implemented in a compact system. This architecture can be easily extended to the system which yields more than two cross-correlations by adding an adequate number of acoustooptic cells in the input plane. This feature is useful for digital communications in which different waveforms are used to represent different messages. Due to the wide bandwidth of acoustooptic cells, this correlator can process broadband communication signals such as frequency-hopping signals.

© 1987 Optical Society of America