Optical spatial phase rectification by limiting quadratic processing in photorefractive two-beam coupling is proposed and demonstrated. We use this limiting quadratic processor to reduce complex multiplicative noise. The principle of compansion (compression and expansion) from serial communication theory is introduced for the first time to our knowledge in parallel optical signal processing. In addition the effect of two-beam coupling compression on the efficiency of beam cleanup is illustrated experimentally and optimized through computer simulation.
© 1994 Optical Society of America
J. Khoury, Jack Fu, Mark Cronin-Golomb, and Charles Woods, "Quadratic processing and nonlinear optical phase rectification in noise reduction," J. Opt. Soc. Am. B 11, 1960-1971 (1994)