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High-diffraction-efficiency pseudorandom encoding

Y.Yang, H. Stark, D. Gurkan
Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL

C. Lawson, R. Cohn
The ElectroOptics Research Institute
Univ. of Louisville, Louisville, Ky.

Abstract

            Pseudorandom encoding (PRE) is a statistics-based procedure in which a pure-phase spatial light modulator (SLM) can yield, on the average, the prescribed diffraction pattern specified by the user. We seek to combine PRE with the optimization of an aperture-based target function. The target function is a fully complex input transmittance, unrealizable by a phase-only SLM, that generates a prescribed light intensity. The optimiza-tion is done to increase the diffraction efficiency of the overall process. We compare three optimization methods—Monte Carlo simulation, a genetic algorithm, and a gradient search—for maximizing the diffraction efficiency of a spot-array generator. Calculated solutions are then encoded by PRE, and the resulting diffrac-tion patterns are computer simulated. Details on the complexity of each procedure are furnished, as well as comparisons on the quality, such as uniformity of the output spot array.

Y.Yang, H. Stark, D. Gurkan, C. Lawson, R. Cohn, "High-diffraction-efficiency pseudorandom encoding," J. Opt. Soc. Am. A 17(2), 285-293 (February 2000)

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