Acousto-optic figure of merit of TeO2 for circularly polarized light

Abstract

The intensity of the diffracted light in an optically active crystal by anisotropic Bragg diffraction has been observed to depend strongly on the polarization condition of the incident light. The acousto‐optic figure of merit for this type of crystal, therefore, should be measured under careful selection of the polarization and geometrical condition of the incident light. The figure of merit Me(p²n⁶/ρv³) of a TeO₂ crystal for the slowest shear sound wave propagation using circularly polarized incident light was found to be 1200 × 10⁻¹⁸ sec³/g at 6328 Å rather than 793 × 10⁻¹⁸ sec³/g, as was previously reported by using arbitrarily polarized light. The previous measurement does not give a correct value of Me, according to the theory given above.