ANGULAR-DEPENDENCE OF PHASE-CONJUGATE INTENSITY IN FORWARD 4-WAVE-MIXING WITH GAUSSIAN-BEAM PUMPING

With progress in phase conjugate optics, studies on forward four-wave mixing have been actively carried out. From the practical optical syst em design point of view, it is important to understand the angular dep endence of phase conjugate intensity when pumping beams with limited s pot size are used, especially with beam separation taken into consider ation. In this paper, the angular dependence of phase conjugate intens ity distribution is theoretically analyzed for the first time, in forw ard four-wave mixing when an optical Kerr medium is used. First, the p hase conjugate intensity is calculated for a nonlinear medium thinner than the overlapping region of two pumping beams, where the intensity is relatively low. The results an used to calculate the output angle o f the phase conjugate beam against the z-axis and the azimuth angle in the x-y plane. Then, a similar analysis is conducted for a medium suf ficiently thick to cover the interaction region of two pumping beams. The differences between the above two cases are described and comparis on with plane-wave pumping is made. Finally, the effects of spot size and curvature variation with Gaussian beam pumping on conjugate beam i ntensity are discussed for the case of a thick medium. (C) 1997 Script a Technica, Inc.