Multiplicative time and space integrating acousto-optic architectures for real time spectrum processing

Multiplicative acousto-optic architectures using time and space dimensions for spectrally resolving long 1-D signals and images are described. The Discrete Fourier Transform algorithm is implemented optically to provide fine frequency resolving power. Experimental results are presented for 1-D and 2-D input signals. Bias removal techniques are discussed, including an approach using a photorefractive crystal as a time integrating bias-free detector.