POLARIZATION-DEPENDENT ACOUSTO-OPTIC EFFICIENCY IN OPTICALLY ACTIVE BIAXIAL alpha-HIO 3 CRYSTALS

The effect of polarization of the incident optical wave on the effective elasto-optic coefficient and the acousto-optic figure of merit in optically active, optically biaxial α-HIO3 crystals is analyzed in the present work.It has been revealed that the increase in both parameters occurs when the polarization of the incident optical wave aligns with the polarization of the eigenwaves at the interaction with the quasi-longitudinal acoustic wave.The acousto-optic figure of merit for the case of acousto-optic interaction with quasilongitudinal AW increases more than two times, reaching almost the same value as the maximal one in the XZ plane of acousto-optic interaction.It has been found that at the fifth and sixth types of acousto-optic interactions with a pure transverse acoustic wave, the acousto-optic diffraction is only possible due to the optical activity and ellipticity of the eigenwaves.In particular, for the sixth interaction type, the acousto-optic figure of merit caused solely by the eigenwaves' ellipticity reaches 13.4×10 -15 s 3 /kg.