In uence of Acoustic Anisotropy on Frequency Bandwidths of Bragg Di raction in Two Orthogonally Polarized Di raction Orders

In uence of Acoustic Anisotropy on Frequency Bandwidths of Bragg Di raction in Two Orthogonally Polarized Di raction Orders A.V. Zakharov* and V.B. Voloshinov Faculty of Physics, Lomonosov Moscow State University, GSP-2, Leninskiye Gory, 119992 Moscow, Russia This paper theoretically and experimentally examines a speci c regime of acousto-optic di raction during which an arbitrarily polarized incident light in a paratellurite crystal is scattered simultaneously into two orthogonally polarized di raction maxima. We examined acoustic energy walk-o in the crystal and its in uence on phase matching as well as on distribution of light energy between the two di raction orders. This in uence was theoretically considered by means of wave vector diagrams illustrating momentum conservation law during the photon phonon interaction. We obtained expressions for mismatch parameters in the ordinary +1 and extraordinary 1 di raction orders both depending on the walk-o angle. The obtained parameters were used in the Raman Nath system of coupled-wave equations to calculate the di racted light intensities and frequency bandwidths of di raction. We measured the bandwidths in experiments carried out in the (11̄0) plane of paratellurite crystal at the walk-o angle equal to 54◦.