MAGNETOPHOTOREFRACTIVE EFFECTS IN DILUTED MAGNETIC SEMICONDUCTORS - THEORY AND EXPERIMENT

Faraday and Voigt magneto-optic effects in undoped Cd1-xMnxTe, a dilut ed magnetic semiconductor, modify nonlinear beam coupling during photo refractive two-wave mixing. Three magnetophotorefractive geometries us ing transmission holographic gratings are identified: (1) the longitud inal Faraday geometry; (2) the transverse Faraday geometry; and (3) th e Voigt geometry. In the magnetophotorefractive phenomena, magnetic-fi eld-induced circular and linear birefringence alters the polarization and phase of coupled modes propagating in the presence of electro-opti c gratings generated by photoinduced space charge. Experimental and th eoretical behavior for each of the geometries is presented as function s of incident beam polarization and magnetic-field strength. The magne tic field controls the magnitude and the direction of nonreciprocal en ergy transfer between the two beams.