Sergei G. Grechin

Optical properties of a nonlinear LiInS{sub 2} crystal

The linear and nonlinear optical properties and the radiation resistance of a LiInS{sub 2} single crystal are studied. Phase matching conditions are calculated for the first time for a LiInS{sub 2} crystal. (nonlinear optical phenomena)

Simulation of thermo-optic coupling in the thermally anisotropic gallium selenide crystal for second harmonic generation

A second harmonic generation model of space-time thermo-optic coupling was proposed in thermal anisotropic nonlinear crystals, where an iterative approach was used to approximate the temperature anisotropy. The coupling process was simulated with the aid of derived analytical formulas in a gallium selenide crystal, pumped by a pulsed carbon dioxide laser. The intensities of the fundamental and harmonic beams, conversion efficiencies and temperature distributions were demonstrated during the evolution processes. The results showed that a compensation for the phase mismatch induced by the thermal effect can mitigate the reduction of conversion efficiency better than temperature control.

Functional possibilities of nonlinear crystals for laser frequency conversion: biaxial crystals

We report the method and results of a complex analysis of phase-matching and nonlinear properties for biaxial crystals of all point groups of symmetry, which determine their functional possibilities in solving various problems of nonlinear frequency conversion of laser radiation.

The influence of thermal deformation processes on frequency conversion in an LBO crystal

The influence of the thermal deformation process on frequency conversion in an LBO crystal is considered. The different temperature bandwidths at the harmonic generation of YAG:Nd laser radiation were obtained experimentally three times at different types of crystal fixation.

Temperature dependence of SHG efficiency by focusing of laser radiation

The paper presents the peculiarities of the temperature dependence for the second harmonic generation efficiency of focusing laser radiation. It is shown that an asymmetry of the dependence is the result of the vector phase-matching process near the crystal axis.

Damage of an AR-coated LBO crystal by laser pulses of microsecond duration

The optical damage of an LBO crystal by laser pulses of microsecond duration at 1.0796 μm and 0.5398 μm is investigated.

LuAB crystal for frequency conversion

In the last decade it synthesized a promising nonlinear crystal aluminum-borate lutetium. The paper presents the evaluation of the applicability of the crystal for various applications of nonlinear optical frequency conversion.

Thermo-optical properties of LBO crystal for angular non-critical phase matching for second harmonic generation along X-axis

Thermo-optical parameters proved to be very important parameters of crystals for nonlinear optical conversion. These parameters allow defining the temperature bandwidth of phase matching, as well as the temperature tuning characteristics. For lithium triborate (LiB3O5, LBO) crystal, there is a possibility to realize the angular non-critical phase matching for second harmonic generation (SHG) along x axis (ssf type of interaction). In this case, one observes both the maximum value of effective nonlinearity coefficient, and the high values of angular bandwidths for two angular coordinates. This possibility is realized in a wide range of wavelengths with variation of crystal temperature.

Periodical double frequency YAG:Nd laserfor pumping parametric amplifier

The goal of this work is to build pulse periodic laser for pumping parametric amplifier of signal radiation with wavelength 1054 nm and energy in the pulse 1 nJ up to the values of several tens mkJ.

Angular phase-matching bandwidths in biaxial nonlinear crystals for frequency converters

It is shown that the angular phase-matching bandwidths in biaxial nonlinear crystals in the general case must be calculated in the coordinate system in which the angular deviations of the crystal and the laser beam divergence are determined consistently. The angular phase-matching bandwidths in this coordinate system may considerably differ from the conventionally determined values. The optimum orientation of the coordinate system for determining the angular phase-matching bandwidths is found. It is established that, in the general case in biaxial crystals, as in uniaxial ones, phase matching is always angle-critical along one coordinate and noncritical along the other and that it is possible to realise angle-noncritical phase matching of the fourth order.