Optical phase conjugation in a nematic liquid-crystal film modulated by a quasi-static electric field

Abstract

A quasi-static field can play an important role in molecular reorientation of the optical nonlinearity in liquid crystals because of the combination of the critical behavior of the sample at the Freedericksz transition and of nonlinear coupling of the optical and quasi-static fields. The nonlinear-optical phenomenon, optical phase conjugation, was observed in an electric-field-biased nematic liquid-crystal film and can be predicted by molecular reorientation calculated with continuum theory. The external field-modulated intensities of the phase-conjugation beams were obtained by both numerical calculation and experimental measurement. At the same time, the rise times of the intensities of phase-conjugation beams were measured for various external fields. (C) 1997 Optical Society of America.