SOLUTIONS TO VECTOR 4-WAVE-MIXING IN CUBIC PHOTOREFRACTIVE MATERIALS

We present an eight-dimensional matrix formulation of vector four-wave mixing. We study the case of a non-optically active photorefractive f or the transmission grating. The coupled equations are represented in a group formalism and irreducible forms are found. We show that when c ross-polarization coupling is neglected, the system of equations is go verned by two coupled SU(2) groups. We develop a theory that allows fo r pump depletion and electric-field-induced bulk birefringence. Analyt ical solutions are found when cubic <(4)over bar 3m> materials are con sidered in two standard experimental geometries, i.e., electric fields perpendicular to the (110) crystal faces and electric fields perpendi cular to the (001) crystal faces. Results are presented that show the effects of linear and circular polarized beams, and the use of these m aterials for vector phase conjugation is discussed. Solution routes to other geometries and noncubic photorefractive materials are also pres ented. (C) 1997 Optical Society of America.