Analysis of transfer function dependence on configuration of acousto-optic interaction in uniaxial crystals

The key characteristic of any acousto-optical device, which describes its angular and spectral selectivity, is a transfer function, which depends on the light wavelength, acoustic power, configuration and length of acousto-optic interaction, refractive indices of the media, etc. The shape of transfer functions was earlier analyzed qualitatively for the most commonly used configurations and several topological types of transfer function were described in uniaxial acoustooptical crystals. For spectral imaging applications, however, this analysis is not sufficient and the detailed quantitative investigation is necessary for any particular diffraction geometry. In this study, we first time demonstrate results of accurate calculation of the transfer function for any incident light direction and any reasonable ultrasound wave angle with account of crystal geometry and parameters. All the topographical types of transfer function are described. These results are important for the development of imaging acousto-optical tunable filters with aberrations correction or with required homogeneity of the transmitted image intensity.