Acousto-optic interaction in LGS and CTGS crystals

Based on the matrices of elastic and elasto-optic coefficients, the extreme surfaces of the spatial distribution of the acousto-optic (AO) figure-of-merit М 2 for langasite and calcium-tantalum gallosilicate crystals are constructed and analyzed. The determined maximal achievable values of М 2 for these crystals are commensurate and twice the maximal value of М 2 for quartz. The most effective AO interaction geometries and geometry of cuts for optimized AO cells are given. The investigated crystals, due to the temperature stability, excellent optical quality, resistance to environmental aggression and high optical damage threshold can be used for AO modulators of the ultraviolet spectral range.