Abstract

This paper deals with a Hughes liquid crystal light valve with feedback operating as an optical multi- level arithmetic storage unit and as a variable frequency diffraction grating. As illustrated In Fig. 1, the Input information is provided through illuminated fibers. Input information is in the form of two points in a spatial frequency plane. These are Fourier transformed, and the resulting parallel line pattern is applied to the light valve in the form of an interference pattern, On the output side the light valve then acts as a controlled diffraction grating. The output pattern is then Fourier transformed to form a spatial zero frequency point and two spatial sidebands. The spatial zero frequency and one sideband are then imaged onto the Input, thus forming the feedback loop. To provide stable rather than neutral equilibrium a holographic diffraction grating is used as a cylindrical lenslet array.

© 1983 Optical Society of America