We present results of theoretical investigation of anisotropic close to collinear acousto-optic interaction in alpha-iodic acid crystal. A comparative analysis of the characteristics of quasi-collinear filters and filters based on close to collinear variant of interaction is carried out. The calculations have shown that filters based on close to collinear variant of interaction are almost as good as quasi-collinear filters in spectral resolution at the same interaction length. It is established that the effect of angular shift of geometry due to the dispersion of directions of biaxial crystal optical axes on the interaction characteristics, in this case, is much less distinct than for the wide-aperture filter in the region of small Bragg angles. This fact opens up possibilities of practical implementation of such devices without geometry of acoustooptic interaction correction.
We present results of theoretical analysis of anisotropic acousto-optic interaction peculiarities in a spatially periodical acoustic field created by a phased array transducer with antiphase excitation of adjacent sections. Contrary to the homogeneous transducer, the transfer function of the acousto-optic cell with the phased array transducer contains two main maxima situated on the opposite sides in regard to the Bragg angle. The calculations have shown that the diffraction efficiency can reach 100% in spite of noticeable acousto-optic phase mismatch. A number of unusual features of light scattering in the spatially periodical acoustic field is revealed, which can be useful at the development of acousto-optic devices of a new type.