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Kindrat I.I.,University of Zielona Gora | Padlyak B.V.,University of Zielona Gora | Padlyak B.V.,Vlokh Institute of Physical Optics | Drzewiecki A.,University of Zielona Gora
Journal of Luminescence | Year: 2015

Abstract The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li2B4O7, LiKB4O7, CaB4O7, and LiCaBO3 compositions were investigated and analysed. The Li2B4O7:Sm, LiKB4O7:Sm, CaB4O7:Sm, and LiCaBO3:Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm3+ (4f5, 6H5/2) ions, exclusively. All observed 4f - 4f transitions of the Sm3+ centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm3+ ions peaked about 598 nm (4G5/2 → 6H7/2 transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm3+ luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm3+ centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd-Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce3+ non-controlled impurity and intrinsic luminescence centres to the Sm3+ centres has been observed. Peculiarities of the Sm3+ local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. © 2015 Elsevier B.V. Source


Adamenko D.,Vlokh Institute of Physical Optics | Kushnirevych M.,Vlokh Institute of Physical Optics | Kokhan O.,Uzhgorod National University | Vlokh R.,Vlokh Institute of Physical Optics
Ukrainian Journal of Physical Optics | Year: 2015

We have studied experimentally the Faraday effect in Tl3AsSe4 crystals. The effective Faraday tensor coefficient and the Verdet constant are determined under normal conditions and λ=632.8 nm. They are equal to 0.06F11+0.94F22=(9.23±0.21)×10-13 m/A and VF=(82.2±1.8)rad/T×m, respectively. We have shown that the Tl3AsSe4 crystals are one of the most efficient magnetooptic materials among magnetically non-ordered ones. © 2015, Institute of Physical Optics. All rights reserved. Source


Mys O.,Vlokh Institute of Physical Optics | Kostyrko M.,Vlokh Institute of Physical Optics | Vlokh R.,Vlokh Institute of Physical Optics
Applied Optics | Year: 2016

We have developed a method for the analysis of anisotropy of an acousto-optic figure of merit (AOFM), which is valid for the case of anisotropic diffraction in the trigonal crystals of the point symmetries 3m, 32, and 3m. The method is verified via the example of LiNbO3 crystals. The relations for the effective elasto-optic coefficients and the AOFM are obtained for the three types of acousto-optic (AO) interactions peculiar for the anisotropic AO diffraction: the interaction of a so-called type VII with a quasi-longitudinal acoustic wave and the interactions of types VIII and IX with two quasi-transverse acoustic waves. The AO diffraction geometries providing maximal AOFM values have been determined for each of the mentioned interaction types. We have found that the maximum AOFM proper for LiNbO3 is equal to 15.9 × 10-15 s3/kg. This value is achieved at the type IX of AO interactions in the interaction plane rotated by 60.0 deg around the principal X axis with respect to the principal X-Z plane. The type VIII of AO interactions is characterized by a comparable AOFM (15.1 × 10-15 s3/kg), which is realized in the Y CZ interaction plane. A close comparison of our results with the available experimental data demonstrates their fairly good agreement. © 2016 Optical Society of America. Source


Vasylkiv Y.,Vlokh Institute of Physical Optics | Skab I.,Vlokh Institute of Physical Optics | Vlokh R.,Vlokh Institute of Physical Optics
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2014

In this work, we analyze the behavior of topological defects of optical indicatrix orientation induced by a conically shaped electric field in crystals in a crossover regime that appears at intermediate fields separating the regimes of prevailing Pockels and Kerr electro-optic nonlinearities. We have found that increases in the electric voltage applied to a crystal induce neither topological defects, with the strengths being not multiples of 1/2, or the optical vortices with fractional charges. Instead, there appear some additional topological defects of the optical indicatrix orientation, the behavior of which we have studied in detail. © 2014 Optical Society of America. Source


Mys O.,Vlokh Institute of Physical Optics | Kostyrko M.,Vlokh Institute of Physical Optics | Vasylkiv Y.,Vlokh Institute of Physical Optics | Vlokh R.,Vlokh Institute of Physical Optics
Ukrainian Journal of Physical Optics | Year: 2015

Anisotropies of the acoustooptic figure of merit (AOFM) and the effective elastooptic coefficient under the conditions of collinear diffraction have been analyzed for LiNbO3 crystals. Narrow peak-like extremes have been revealed in the dependences of AOFM upon the orientation angle of the wave vector of the incident optical wave. We have also explained the reasons for the angular instability of the AOFM and the effective elastooptic coefficient. © 2015, Institute of Physical Optics. All rights reserved. Source

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