Vladimir P. Solntsev

Growth of α-BaB2O4 single crystals from melts at various compositions: comparison of optical properties

Abstract The conditions for growing bulk α-BaB2O4 single crystals from stoichiometric melts and high-temperature solutions as well as some associated problems are reported. The morphology of crystals, formation of inclusions and light scattering depending on crystal growth conditions are described. Comparative estimation of spectral characteristics and of the optical quality, as well as the damage threshold of crystal samples suitable for production of polarization devices of laser systems have been performed.

BeAl6O10:Cr3+ (Ti3+, Ni2+) laser crystals and their spectroscopic characteristics

Abstract The EPR, optical absorption, luminescence spectra, and lasing characteristics of Cr 3+ , Ti 3+ , and Ni 2+ ions in BeAl 6 O 10 (beryllium hexaaluminate, BHA) crystals are studied. The spectroscopic data show that the BHA crystals have an orthorhombic structure with the space group Pbcm. The temperature dependence of luminescence lifetime of the excited state of Cr 3+ ions ( τ ≈13×10 −6 s at 300 K) is investigated. The energy gap between the 2 E- and 4 T 2 -levels of Cr 3+ (∼236 cm −1 ) and the nonradiative relaxation activation energy ( E a ≈1667 cm −1 ) are determined. High-efficient tunable radiation of a new BeAl 6 O 10 :Cr 3+ laser crystal is demonstrated in the region of 0.78–0.92 μm at 300 K. It is shown that the doped BHA crystals are promising active media for tunable solid state lasers in the spectral regions of 0.7–1.0 μm (Cr 3+ ) and 1.35–1.65 μm (Ni 2+ ).

Origin of defects in nonlinear BBO crystals

Defects in nonlinear optical barium metaborate crystals (?- and ?-BBO) have been investigated by means of optical spectroscopy and thermal activation methods. Low-temperature absorption peaks have been observed in all samples. The dependence of these peaks upon crystalline phase and type of the flux used while growing is low. This fact indicates that intrinsic defects play the leading role in absorption.. It is shown that while growing BBO crystals by TSSG technique, defects, which form deep electron-type traps in the forbidden gap, are generated.

Origin of near-ultraviolet absorption of nonlinear BBO crystals

Defects in nonlinear optical barium metaborate crystals have been investigated by means of optical spectroscopy and thermally activational methods. Low-temperature absorption peaks have been observed at all samples. The dependence of these peaks upon crystalline phase and type of the flux used while growing is low. This fact indicates that intrinsic defects play the leading role in absorption origination. It is shown that while growing BBO crystals by TSSG technique, defects, which form deep electron-type traps in the forbidden gap, are generated.

Growth and crystal structure of the BeAl6O10 single crystals

Abstract Unlike earlier published works we have established incongruent melting for the compound BeAl6O10 (BHA). The conditions of growing crystals from their own melt with a superstoichiometric excess of BeO, using the Czochralski method, have been determined. The nature of inclusions in grown BHA crystals is described. On the basis of X-ray crystal structure analysis and data of spectroscopic studies the symmetry and space group of BHA crystal structure have been refined, as well as uncertainties arising in their interpretation are discussed.