Phase-conjugation and spatial-frequency dependence of wave-front reflectivity in Bi_12SiO_20 crystals

Abstract

Dependence of phase-conjugate wave-front reflectivity on the spatial frequency of the dynamic hologram recorded in Bi12SiO20 crystals is analyzed. Depending on the respective values of applied field E0 and fringe spacing Λ, drift or diffusion of the photocarriers dominates the space-charge buildup and affects the phase-conjugate wave-front intensity differently. It is demonstrated that the modulation transfer function of the coherent four-wave process mixing can be controlled by the amplitude of externally applied field E0. Experimental results are interpreted on the basis of the dynamic theory of Kukhtarev et al.