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Pseudorandom Phase-Only Encoding of Real-Time Spatial Light Modulator

Robert W. Cohn and Minhua Liang,
Univ. of Louisville, Louisville, Ky.

Abstract

            We previously proposed a method of mapping full-complex spatial modulations into phase-only modulations. The Fourier transform of the encoded modulations approximates that of the original complex modulations. The amplitude of each pixel is encoded by the property that the amplitude of a random-phasor sum is reduced corresponding to its standard deviation. Pseudorandom encoding is designed for phase-only spatial light modulators that produce 360° phase shifts. Because such devices are rare, experiments are performed with a 326° modulator composed of two In Focus model TVT6000 liquid-crystal displays. Qualitative agreement with theory is achieved despite several nonideal properties of the modulator. Key words: Optical information processing, spatial light modulators, liquid-crystal televisions, phase-only filters, laser speckle, rough-surface scattering, statistical optics, binary and diffractive optics, phased arrays, measurements of phase.           ©1996 Optical Society of America

R. W. Cohn and M. Liang, "Pseudorandom Phase-Only Encoding of Real-Time Spatial Light Modulators," Applied Optics, 35(14), 2488-2498. (10 May 1996)

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