Abstract

Multichannel acoustooptic Bragg cells have been proposed for correlation, spectrum analysis, phased array signal processing, and optical computing. Concerns were expressed on the effects of crosstalk in the multichannel Bragg cells due to acoustic spreading and rf interference on the systems performance. We have evaluated several high-performance multichannel TeO₂ Bragg cells to determine their suitability for our advanced hybrid optical signal processing needs. Crosstalk, among other parameters, was measured and found to be around −30 dB. We report our recent measurements of the effects of the crosstalk of these multichannel TeO₂ Bragg cells on multichannel AO correlators, convolvers, and spectrum analyzers, which form the basic building blocks for some advanced architectures. Experiments were done on a coherent space-integrating correlator that was used for broadband beam forming and a similar convolver for digital multiplication by analog convolution. Results showed that the signal in a quiescent channel due to crosstalk from the neighboring activated channel were significant and could cause false alarm and bit errors. Experiments with an AO rf spectrum analyzer also showed significant extraneous spectral components due to crosstalk from neighboring channels. Details of the study are presented.

© 1988 Optical Society of America