A femtosecond Kerr shutter was demonstrated using a lead–bismuth–gallate oxide glass. The optical gating time was measured to be less than 350 fs and the peak Kerr transmittance was found to be 2.3 times larger than that of the standard Kerr CS2 liquid medium, giving nonlinear Kerr coefficient n2=4.4×10−11 esu.

Single crystals of the composition Na3PO4 have been grown from Bur. The unit-cell parameter of the cubic crystals at room temperature was refined to a value of a = 7.424(1) Angstrom; the atomic coordinates were refined within the sp. gr. Fm3m. Electric conductivity of single crystals equals (2-4) X 10(-3) Omega (-1) cm(-1) at 300 degreesC. The electron component of conductivity is less than the ionic one by three orders of magnitude. (C) 2000 MAIK "Nauka/Interperiodica".

Cr4:Ca2GeO4 crystals were grown by pulling technique from CaF2-based solution. RF-heated Czochralski equipment designed for conventional growth procedure from a melt was employed. Stable growth conditions without constitutional supercooling have been created for the pulling rate up to 0.25mm/h. Only Cr4+-substitution took place in the Ca2GeO4 crystal sites whether the growth atmosphere was nitrogen or air.

Continuous-wave tunable laser operation all-solid-state Cr4+:Mg2SiO4 (Cr:forsterite) and Cr4+:Ca2GeO4 (Cunyite) has been demonstrated. A master oscillator power amplifier semiconductor diode laser was utilized to pump both Cnforsterite and Cunyite. Diode-pumped Cnforsterite was tunable over the 1236-1300-nm spectral range, generating a maximum output of 10 mW at 1260 nm for 640 mW of pump power absorbed by the crystal. Diode-pumped Cunyite was also demonstrated. A maximum output power of 20mW was measure at 1420 nm and the observed tuning range was 1390–1473. A fiber laser was also used to pump Cunyite. A maximum output power of 240 mW was measure from the Cunyite laser for 2.6 W absorbed pump power.

Large crystals of highly doped Cr(4+):Ca(2)GeO(4) were grown by a top-seeded solution growth method. Absorption and emission measurements for various crystal orientations have been performed. From the spectroscopic measurements, the only optically active center was identified as tetrahedrally coordinated Cr(4+). Gainswitched, tunable laser operation of Cr(4+):Ca(2)GeO(4) crystal was demonstrated. Pulse energies of 0.4 mJ at 1.4 microm have been generated at a repetition rate of 100 Hz. Tunability over the 1348-1482-nm spectral range has been demonstrated.

Crystals of RE-substituted Bi-Sr-Ca-Cu-O (2212) superconductors (RE = Y, Er, Yb) were grown by a modified self-flux growth technique. A two-stage process with preliminary melt quenching was used to prepare well-defined platelet crystals with thicknesses of up to 5–20 μm. The mechanism of crystallization in sealed cavities is considered. The RE-substituted crystals show a decrease of Tc with increase of RE content in crystals up to the loss of superconducting properties at a complete substitution Ca → RE(Y). The superconducting properties of Bi2Sr2Ga1-xRExCu2Oy crystals are improved after air annealing at 750°C.

Crystallization of high-temperature superconductors was studied in La-Sr-Cu-O, Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O systems. Platelet crystals YBa2Cu3O6.5+x were obtained by spontaneous crystallization from homogeneous nonstoichiometric melts enriched in barium and copper oxide. La2−x Sr x CuO4 was prepared by slow cooling of melts enriched in copper oxide. Bi2(Sr,Ca) n + 1Cu n O y , (n=1; 2) was obtained by melting zone travelling. The crystals show transition to superconducting state atT=93 K, ΔT 0.2–0.5 K (Y, Ba cuprate),T=87 K, ΔT 2K (Bi, Sr, Ca-cuprate). La, Sr-cuprate single crystals obtained by Czochralski method did not show transition to superconducting state. For flux-grown crystalsT c was 5–26 K depending on the composition, growth and heat treatment. The short characterization of some accessory phases (Ba3Y2Cu3PtO10, Ca1.75Sr1.5Cu0.75PtO6, BaCuO2, Ba41Cu44O84Cl2) is reported.

Superionic conductors Li3M2(PO4)3 have been prepared by solid-phase and hydrothermal synthesis, from flux and melt. Single crystals were used in precision structural and electrophysical measurements. The specific features of atomic structure of α-, β-, and γ-phases of Li3M2(PO4)3 have been determined. The ionic and electronic conductivities of ceramics and single crystal Li3Sc2(PO4)3 have been investigated. The influence of isomorphic displacements on phase transition temperature and the values of conductivity have been established.