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It has been shown for the first time that the electric field can enhance the acousto-optic (AO) figure of merit due to the induced ellipticity of eigenwaves through the electro-gyration effect. As a result of the analysis, we have revealed that for the isotropic types of interaction, the increasing of the strength of the electric field results in the broadening of the full width at half maximum (FWHM) of the peak of the AO figure of merit, while almost does not affect the maximal value of this peak. The FWHM of the peak of the AO figure of merit tends to saturation with increasing electric field strength. For anisotropic types of diffraction, the peak of the AO figure of merit is not observed, but with increasing the electric field strength, the surface of the AO figure of merit is expanded. [ABSTRACT FROM AUTHOR]

This work theoretically tested the possibility of expanding the spectrum of vortex charges generated using multi-cascade optical systems based on LiNbO3 crystals twisted around their optical axis. As a result, analytical expressions for the electric field parameters of the output optical wave were obtained for the four main types of elementary cascades that allow the generation of vortices with charges +1 and –1 and also provide the matching of adjacent cascades in the multi-cascade optical system. At the same time, it was shown that when using the appropriate number of sequentially located cascades, each of which belongs to a certain type from the above, it is possible to generate a vortex beam with arbitrary integer vortex charges, including zero. Using the proposed cascade system, one can operate the outgoing beam parameters. This system can be used at the vortex beam multiplexing for information transfer. [ABSTRACT FROM AUTHOR]

The present work is devoted to analyzing the influence of the ellipticity of acoustic waves caused by acoustic activity on the efficiency of acousto-optic interaction. It has been shown that the peak-like increase of the effective elastic-optic coefficients and acousto-optic figure of merit is manifested in the case when the acousto-optic diffraction appears on the quasi-transverse elliptical (or circular) acoustic waves that propagate in the directions that are close to the acoustic axes. In this paper, the analysis has been carried out on the example of quartz crystals, and it has been shown that the increase of acousto-optic figure of merit is peculiar for all types of acousto-optic interactions with the quasi-transverse acoustic waves. We have shown that accounting for the ellipticity of diffracted optical waves in the analysis of acousto-optic interaction in optically active crystals leads to more correct results than those obtained in our recent works. [ABSTRACT FROM AUTHOR]

We introduce corrections to our recent article [1. O. Mys, D. Adamenko and R. Vlokh. 2023. Influence of Faraday elliptical birefringence on the acousto-optic diffraction efficiency: a case of isotropic interaction with quasi-longitudinal acoustic waves in KH2PO4 crystals. 24(1): 95-103.]. [ABSTRACT FROM AUTHOR]

In this work we show that the critical exponents of the order parameter (CEOPs) of diffuse ferroelectric phase transitions (DFEPTs) occurring in lead germanate-based crystals can be determined using experimental temperature dependences of their optical rotation. We also describe the approach that suggests dividing a crystal sample into many homogeneous unit cells, each of which is characterized by a non-diffuse phase transition with a specific local Curie temperature. Using this approach, the CEOPs have been determined for the pure Pb5Ge3O11 crystals, the solid solutions Pb5(Ge1-xSix)3O11 (x = 0.03, 0.05, 0.10, 0.20, 0.40) and (Pb1-xBax)5Ge3O11 (x = 0.02, 0.05), and the doped crystals Pb5Ge3O11:Li3+ (0.005 wt. %), Pb5Ge3O11:La3+ (0.02 wt. %), Pb5Ge3O11:Eu3+ (0.021 wt. %), Pb5Ge3O11:Li3+, Bi3+ (0.152 wt. %) and Pb5Ge3O11:Cu2+ (0.14 wt. %). Comparison of our approach with the other techniques used for determining the Curie temperatures and the CEOPs of DFEPTs testifies to its essential advantages. [ABSTRACT FROM AUTHOR]

Today, spelt wheat grain is used to produce high quality food. Intermediate wheatgrass is a promising crop for prairie restoration. One of the elements of biologization is the influence of growing crops on the microbiota of soil rhizosphere. The microbiota of spelt wheat and intermediate wheatgrass soil rhizosphere remains insufficiently studied. Aim. To study the number of individual groups of microbiota in dynamics in the rhizosphere of cereal crops (spelt wheat, intermediate wheatgrass) depending on the weather conditions and the phase of plants development. Methods. Classical microbiological, statistical methods were used in the work. In particular, the study of the number of microorganisms of different ecological and trophic groups (ammonifying, nitrifying, cellulolytic and nitrogen-fixing) was carried out according to generally accepted methods in soil microbiology. The reliability of the influence of factors was determined by the probability value «р» level which was calculated using STATISTICA 8 program. Results. The amount of ammonifying and cellulolytic microorganisms in the soil rhizosphere of spelt wheat is significantly higher compared to soft wheat. The rhizosphere microbiota amount of the intermediate wheatgrass on the 2-3 year of cultivation was more resistant to adverse environmental factors compared to soft wheat. The soil rhizosphere microbiota did not change a lot depending on the phase of plant development during the vegetation period of cereal crops (spelt wheat, intermediate wheatgrass). Conclusions. The formation of rhizosphere microbiota of spelt wheat and intermediate wheatgrass was first analyzed under the conditions of the Right-Bank forest-steppe of Ukraine. The conducted studies indicate the feasibility of growing and use of spelt wheat in breeding programs to create cultivars of soft wheat with higher activity of rhizosphere microbiota. The number of ammonifying, nitrifying and cellulolytic microorganisms of soil rhizosphere of intermediate wheatgrass was significantly higher compared to soft wheat during all growth stages. The conducted studies confirm the practical application of intermediate wheatgrass to preserve and increase soil fertility. Intermediate wheatgrass can be grown for up to three years in one field, as microbiological activity reaches its maximum development. [ABSTRACT FROM AUTHOR]

The research was carried out in 2017-2019 in the conditions of the Right-Bank Forest Steppe of Ukraine. The results of study, the effect of spraying by certain amino acids; salicylic(300 ppm), gibberellin (150 ppm) and ascorbic acids (200 ppm) on garlic (Allium sativum L.) plants are presented in the article. It was found that amino acid solutions improves the antioxidant state: the activities of SOD, CAT, POD, GR, GST in treated leaves tended to increase, the activity of SOD was higher than the control of 7.5-15.0%; CAT (27.4-45.9%); POD (7.0-83.0%); GR (5.4-49.9%); and GST (14.8-41.3%). It was noted that the content of chlorophyll a+b in the leaves significantly increased (2.6-10.8%), The use of amino acids increased the accumulation of dry matter by 1.4-4.0%. The yield increase was 1.14-2.27 t ha-1 (7.7-15.3% compared to control). The content of B vitamins in the garlic cloves was greatly influenced by gibberellic acid, where increasing the amount of B vitamins reached to 21.9% relative to control The use of salicylic and ascorbic acids increased the amount of B vitamins by 7.6 and 8.2%, respectively. The most significant increasing of C vitamin content was observed by spraying of plants with ascorbic acid (+12.5%), whereas by spraying with salicylic and gibberellic acids its content increased by 6.0 and 7.5%, respectively. In the future, the data obtained can be used to reduce the impact of abiotic factors on the physiological state and productivity of garlic plants. Also, the obtained data will serve as a theoretical basis for producers in view of the purposes for which the products are grown (for sale in fresh form, processing or storage). [ABSTRACT FROM AUTHOR]

We study experimentally the temperature dependences of relative elongation in thallium gallium diselenide crystals, TlGaSe2, in the temperature region 100–293 K. The eigenvalues of thermal expansion tensor are determined. The anisotropy of thermal expansion for TlGaSe2 within the cleavage plane is revealed. We find that the temperature dependences of the relative elongations and the thermal expansion coefficients are characterized by a number of anomalies which correspond, most probably, to structural phase transitions among different polytypes. Relations between the anomalous temperature behavior of thermal expansion and the polytype structure of TlGaSe2 are discussed. [ABSTRACT FROM AUTHOR]

Based on experimental studies of acoustic wave velocities in TlInSe2 crystals, all components of their elastic stiffness and compliance tensors are determined. TlInSe2 has three acoustic axes parallel to the principal crystallographic directions. The lowest velocities of acoustic eigenwaves are used to estimate the acousto-optic figure of merit. We analyse deviations from purely longitudinal and transverse polarization states, as well as the obliquity of acoustic energy flow. Temperature dependences of strains along the three principal crystallographic directions and of acoustic wave velocities v11, v22 and v33 are measured. Anomalous behaviour of these parameters occur at T1245 K and T2145 K. It is shown that the symmetry of TlInSe2 becomes lower than tetragonal below the temperature point T1. [ABSTRACT FROM AUTHOR]

Basing on the thermal expansion studies performed for β-TlInS2crystals in the course of their phase transitions, we have found that the crystals aged for one year are composed from at least two polytypes, which undergo phase transitions at different temperatures. The detailed analysis of anisotropy of the thermal expansion demonstrates that all of the diagonal components of the thermal expansion tensor associated with the eigensystem have almost the same modules but differ by their signs. This leads to appearance of an elliptical conical surface of zero thermal expansion. The orientation of this surface does not depend on the temperature in the temperature interval under study. We have also found that the thermal expansion coefficients along the crystallographicaandbaxes are close to zero. [ABSTRACT FROM AUTHOR]

We have studied experimentally the Faraday effect in TlInS2 crystals. The Verdet constant VF and the effective Faraday coefficient 'F33 are determined at the light wavelength λ= 632.8 nm under normal conditions. These parameters are equal to VF = (112.4 ±1.5) rad/(T×m) and 'F33=0.9995F33 + 0.0005F11 = = (12.96 ± 0.18)×10-13 m/A , respectively. We have shown that, among magnetically non-ordered substances, TlInS2 represents an efficient magnetooptic material. [ABSTRACT FROM AUTHOR]

We have studied experimentally Faraday effect and thermal expansion for AgGaGeS4 crystals. The Verdet constant VF and the effective Faraday coefficient F'11 are determined at the light wavelength λ = 632.8 nm under normal conditions. They are equal to VF = (7.83±0.21)rad/(T×m) and F'33 = 0.98F33 + 0.02F11 = (1.40±0.04)×10-13 J m/A . The principal thermal expansion coefficients of AgGaGeS4 under normal conditions are equal to α11 =(2.51 ±0.31)× 10-6 K-1, α22 =(3.98 ±0.26) ×10-6K-1 and α33 =(5.63 ±0.36) ×10-6K-1. They are temperature-independent at 300-600 K. [ABSTRACT FROM AUTHOR]

We have obtained phenomenological relation for the Poynting vector of electromagnetic wave propagating in crystals that possess a so-called weak optical activity. The appearance of transverse component of the Poynting vector and a transverse shift of the optical beam due to spin-orbit interaction are discussed. [ABSTRACT FROM AUTHOR]

We present the results for the small-angular mapping of the Faraday effect in single CdS crystals under the operation of light wave vector reversal. It is shown that within experimental accuracy, the magnitude of the optical Faraday rotation, averaged for the angle of laser beam divergence, does not differs for the opposite directions of the wave vector. [ABSTRACT FROM AUTHOR]

We demonstrate experimentally that acousto-optic diffraction by a shear acoustic wave propagating in fused silica can transform linear or circular polarization states into their orthogonal counterparts. It is also shown that a corresponding acousto-optic cell with a shear acoustic wave propagating in a vitreous medium can be used as a NOT or CNOT gate. The advantage of our method is a possibility for spatial manipulation by qubits via acousto-optic diffraction under condition of changing frequency of the acoustic wave. [ABSTRACT FROM AUTHOR]

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. The phase of the beam changes by the angle 2 π whenever the azimuthal angle is changed by the same value. We also study acousto-optic diffraction of the optical beam by the acoustic beam bearing a vortex and demonstrate that each of the appropriate diffraction maxima are split into two maxima. The latter correspond to diffraction by the elementary acoustic rays which are close to the opposite edges of the acoustic vortex beam. A dark region between the maxima appears due to destructive interference of the elementary optical rays originated from the diffraction by the opposite sides of the acoustic vortex beam, which are phase-shifted by π .

We determine full matrices of piezo-optic and elasto-optic coefficients for lead germanate crystals, P b 5 G e 3 O 11 , 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 P b 5 G e 3 O 11 crystals can be obtained only with single-domain samples, since the domain structure induces a number of features that make the final results unreliable. We demonstrate that the acousto-optic figures of merit reach high-enough values at the isotropic acousto-optic interactions with longitudinal acoustic waves propagating along the principal x and z axes (63×10 -15 and 37×10 -15 s 3 / k g ), respectively. At the same time, the efficiency of the acousto-optic interactions with transverse acoustic waves is low. The same is true concerning anisotropic acousto-optic diffraction, since the appropriate elasto-optic coefficients are small enough.

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 Tl 3 AsS 4 crystals, the highest AO figures of merit, M 2 =1290×10 -15 s 3 /kg and M 2 =1305×10 -15 s 3 /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.

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. Our analysis carried out on the example of Tl 3 As S 4 crystals reveals that the deviation of AW polarization from its pure states influences the anisotropy of the AO figure of merit only when the AO interactions with quasi-transverse AWs are dealt with. This fact is caused by the peculiar acoustic and elasto-optic properties of Tl 3 As S 4 . On the other hand, the situation can become different for other crystalline materials, where the angular dependences of the AO figure of merit can differ significantly in cases in which the deviation angle increases. This holds true for the AO interactions with both quasi-transverse and quasi-longitudinal AWs. Under these conditions, non-orthogonality of the AWs (or deviation from their longitudinal polarization states) affects essentially the AO characteristics. Finally, we determine the geometries of AO interactions for which the highest AO figures of merit are reached for the Tl 3 As S 4 crystals.

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 (3.96±0.82)×10 -17   m 3 /N.

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.