ИСТИНА

Acoustic and acousto-optic characteristics of a biaxial crystal HIO3 are investigated theoretically. Calculations of frequency dependences of the Bragg angle for different directions of acoustic wave propagation are carried out for the first time. Most attention is given to the anisotropic diffraction in the region of optical axes. Great variety of these dependences is noted in comparison with uniaxial crystals. This peculiarity makes it possible to choose optimal cuts at creating acousto-optic devices. Calculations of acousto-optic figure of merit are produced for different propagation directions of interacting optical and acoustic waves. It is found in particular that an HIO3 based collinear filter can exceed well-known calcium molybdate filters by 2 times in resolution and by 3.5 times in power consumption.