Abstract: Combined acousto-optic device formed by a cut from optically birefringent single crystal whose one face, parallel to the direction of the principal crystallographic axis, is provided with at least one piezoelectric source of acoustic waves. At that, the normal to the entrance face of the ordinary and extraordinary light beam is inclined from the direction of principal crystallographic axis by an angle .rho. defined by formula.rho.=arc tg(n.sub.e /n.sub.o).+-.20.degree.,in which the symbols n.sub.e and n.sub.o denote the refractive indices of the extraordinary and ordinary light beams in the single crystal.

Abstract: A single crystal of pure or mixed univalent mercury halide, is formed to have a pair of opposite faces polished for entrance and exit of the light wave at least one of the faces of this pair is perpendicular to a direction inclined about a crystallographic direction by a given angle, from the optical axis of the crystal. Another face, provided with a source of acoustic waves, makes an angle of 90.degree. with the at least one face of the pair of faces.

Abstract: A single crystal of pure or mixed univalent mercury halide, which is formed having a pair of opposed polished faces at least one of which is perpendicular to a direction which is inclined from the optical axis of the crystal about the crystallographic direction by an angle between 0.2.degree. to 20.0.degree.. Another face of the crystal is provided with a source of transverse acoustic waves.

Abstract: A single crystal of pure or mixed univalent mercury halide is formed having a first face perpendicular to the direction [A] which is inclined about the crystallographic direction [110] by an angle .alpha.. The crystal is simultaneously inclined from the crystallographic direction [110] about the direction [A] by an angle .beta. so that the two opposite faces for entrance and exit of the light wave are parallel to the direction [A] and [B]. The first face of the parallelepiped is provided with an acoustic wave.