RESUMEN
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 Z. We determine the geometry of AO interactions at which the highest AO figure of merit can be expected. Finally, we show that, in the case of propagation of diffracted light along one of the optic axes in the biaxial Tl3AsS4 crystals, the highest AO figures of merit, M2=1290×10-15s3/kg and M2=1305×10-15s3/kg, can be reached when the quasi-longitudinal acoustic wave interacts with the quasi-ordinary or quasi-extraordinary optical waves in the plane of optic axes.
RESUMEN
We develop a technique for analyzing the anisotropy of an acousto-optic figure of merit for crystals belonging to tetragonal symmetry groups 4/m, 4, and 4¯. The technique is based on phenomenological relations that describe anisotropies of the effective elasto-optic coefficients and the acoustic wave velocities. Our approach is verified on the example of NaBi(MoO4)2 crystals for all possible types and geometries of acousto-optic interactions. We list and characterize the acousto-optic interaction geometries at which the maximal acousto-optic figures of merit are reached for both isotropic and anisotropic interaction types. Finally, we show that the acousto-optic efficiency of NaBi(MoO4)2 originates mainly from large elasto-optic coefficients.
RESUMEN
We report the results of comprehensive studies of the piezo-optic and elasto-optic effects in lithium tetraborate crystals, Li2B4O7. The full matrices of piezo-optic and elasto-optic coefficients are obtained using a recently developed method based on four-point bending. On this basis, we have estimated the acousto-optic figure of merit for Li2B4O7.
RESUMEN
We have developed an approach for analyzing the anisotropy of the acousto-optic figure of merit (AOFM) for lithium niobate crystals in the case of isotropic acousto-optic (AO) diffraction. The working relations for the effective elasto-optic coefficients and the AOFM have been derived. We have found that, under the conditions of isotropic AO diffraction, the maximum AOFM value for LiNbO3 is equal to 11.62×10(-15) s(3)/kg. This is peculiar for the geometry of AO interaction of the shear acoustic wave propagating in the Y-Z plane (the velocity 3994 m/s) with the optical wave polarized in the same plane. We have demonstrated that the maximum AOFM values are achieved mainly due to the essential anisotropy and high values of the elasto-optic coefficient of LiNbO3.
RESUMEN
We present comprehensive experimental measurements and analysis of anisotropy of the acoustic wave velocities for TI(3)AsS(4) crystals, including the obliquity and nonorthogonality of the acoustic waves, and the deviations from purely longitudinal and transverse polarization types. We have found that the crystals under analysis are characterized by rather low transverse wave velocities v(23) and v(32), which are both equal to 630 m/s. It is shown that the efficiency of acoustooptic (AO) interactions in TI(3)AsS(4) can be notably increased when providing anisotropic interaction with the slowest transverse acoustic wave. Under the previously mentioned conditions, the AO figure-of-merit can be estimated to be extremely high, i.e., approximately 3×10(-12) s(3)/kg.
RESUMEN
We suggest a new approach for analyzing spatial anisotropy of an acousto-optic figure of merit (AOFM). The relations for the effective elasto-optic coefficients and the AOFM are derived for all possible types of acousto-optic (AO) interactions in optically isotropic media, including nonsolid-state and solid-state amorphous media and crystals belonging to the cubic system. Our approach allows for finding the optimal geometries of AO interactions characterized by the highest AOFM for a given material. The analysis is carried out on the examples of cubic KBr and KAl(SO4)2 × 12H2O crystals, which represent different subgroups of the cubic symmetry class.
RESUMEN
We show that a system of glass disks compressed along their diameters enables one to induce a doubly charged vortex beam in the emergent light when the incident light is circularly polarized. Using such a disk system, one can control the efficiency of conversion of the spin angular momentum to the orbital angular momentum by a loading force. The consideration presented here can be extended for the case of crystalline materials with high optical damage thresholds in order to induce high-power vortex beams.
RESUMEN
We have revealed a large Faraday rotation in tin thiohypodiphosphate (Sn(2)P(2)S(6)) crystals, which makes this material promising for magneto-optics. The effective Faraday tensor component and the Verdet constant for the direction of the optic axis have been determined by measuring the pure Faraday rotation in Sn(2)P(2)S(6) crystals with both the single-ray and small-angular polarimetric methods at the normal conditions and a wavelength of 632.8 nm. The effective Verdet constant is found to be equal to 115 rad/T x m.