Theory of photorefractive vectorial wave coupling in cubic crystals

We present an analytical theory of vectorial wave coupling in photorefracti ve cubic crystals which are, in general, optically active. The theory is ba sed on the systematic use of the spatial symmetry properties and the appara tus of the Pauli operators to deal with two-dimensional vectors and matrice s. It allows one to give a unified description of a wide spectrum of photor efractive phenomena, including the efficiency and polarization properties o f Bragg diffraction, polarization two-beam coupling enhanced by ac fields, the influence of the photoelastic effect, etc. Applications of the theory t o crystals of the sillenite family and to particular photorefractive phenom ena are given. A good qualitative agreement between the theoretical predict ions and experimental data for Bi12TiO20 (BTO) crystals is shown. [S1063-65 1X(99)12209-8].