Generation of acoustic vortices and acousto-optic interactions with acoustic vortex beams.

We demonstrate the generation of acoustic vortex beams with the aid of an acoustic spiral phase plate and an acoustic grating having a fork-like bifurcation of its slits. The acoustic vortex beam generated in this manner influences the particles floating on a water surface and rotates them. Our experiments show that the intensity of the acoustic vortex beam increases from zero in its center to a certain maximal value near the shell of the beam.

Experimental determination of full matrices of the piezo-optic and elasto-optic coefficients for PbGeO crystals.

We determine full matrices of piezo-optic and elasto-optic coefficients for lead germanate crystals, , using Dixon-Cohen and interferometric methods. Two different types of samples are studied, single- and multi-domain. We show that the correct data for the crystals can be obtained only with single-domain samples, since the domain structure induces a number of features that make the final results unreliable.

Anisotropy of acousto-optic figure of merit for the case of a Bragg-diffracted wave propagating along an optic axis in optically biaxial crystals: TlAsS crystals.

In the present work, we analyze acousto-optic (AO) interactions under the condition when a diffracted optical wave propagates along one of the optic axes in optically biaxial crystals. We find that the number of AO interaction types is reduced from nine, which is typical for the most general case, to six, since some of the isotropic and anisotropic diffraction types manifest themselves simultaneously. We reveal that, in the case of the interactions of quasi-ordinary and quasi-extraordinary optical waves, the dependences of effective elasto-optic coefficients and AO figure of merit on the tracing angle of an incident optical beam around the optic axis are symmetric with respect to the plane that is perpendicular to the plane of optic axes and contains the principal axis .

Acousto-optic interaction between circularly polarized optical eigenwaves: example of AgGaS crystals.

We analyze acousto-optic (AO) diffraction occurring at the light wavelength of a so-called "isotropic point" in AgGaS crystals. It is shown that a natural optical activity, which manifests itself as circular birefringence at the isotropic point, can lead to two different types of AO Bragg diffraction, isotropic and anisotropic. The first type concerns the interaction of circularly polarized optical eigenwaves with the same sign of rotations of their electric-field vectors.

Effect of deviation from purely transverse and longitudinal polarization states of acoustic waves on the anisotropy of acousto-optic figure of merit: the case of TlAsS crystals.

We analyze the effect of acoustic wave (AW) polarization states deviation from purely longitudinal and transverse on the anisotropy of the acousto-optic (AO) figure of merit for the case of AO interactions occurring in the principal crystallographic planes. In particular, we obtain phenomenological relations that describe the effective elasto-optic coefficient for the six types of AO interactions, which exhaust all of the possible isotropic AO diffractions. These relations are compared for the alternative cases when the deviations of polarization of the AWs from purely longitudinal and transverse ones are either taken into consideration or completely neglected.

Torsion-induced optical rotation in isotropic glass media.

We have revealed that torsion stresses produce an optical activity effect in initially isotropic glass media. The optical activity caused by spatially inhomogeneous mechanical stresses has been experimentally studied for a standard glass BK7 subjected to torques, using a single-beam polarimetry and a polarizer-sample-analyzer scheme. The torsion-gyration coefficient for the BK7 glass has been determined as (3.