[en] The Jones matrix method is used to study the optimal conditions for steady-state generation through intracavity frequency conversion in a solid-state laser under type-II phase matching based on a weakly anisotropic model of an active medium (amplitude and phase anisotropy) and a nonlinear element. The optimal rotation angles of the nonlinear element are found. (nonlinear optical phenomena)

[en] The Jones matrix method is used to analyse the polarisation eigenmodes of a solid-state laser with an anisotropic Fabry - Perot cavity containing amplitude and phase anisotropic elements. The results demonstrate that, when the axes of these elements do not coincide, the eigenpolarisations become elliptical and nonorthogonal. The ellipticities and azimuths of the polarisation modes and the magnitude and phase of the nonorthogonality parameter are determined as functions of polariser angle at different relationships between the amplitude and phase anisotropies, and the effect is shown to be strongest at a polariser angle of 45⁰. There is critical phase anisotropy, dependent on amplitude anisotropy, at which the magnitude of the nonorthogonality parameter and ellipticity of the polarisation modes approach unity. (resonators)

[en] The kinetics of vertical electron transport in a semiconductor superlattice is considered taking into account partial localization of electrons. The time dependences of photoemission currents from samples based on a strained semiconductor superlattice calculated by numerically solving the kinetic equation are in good agreement with experimental data. Comparison of the theory with experiment makes it possible to determine the characteristic electron localization and thermoactivation times, the diffusion length, and losses of photoelectrons in the superlattice

[en] Optimal photocathode performance requirements and recent developments of highly efficient emitters of polarized electrons are reviewed

[en] The results of experimental and theoretical studies of spin polarized electron transport in semiconductor SL used for photoemitter application are presented. The experimental study is based on the time resolved measurements of electron emission from the cathode after its photoexcitation by fs laser pulse. The response and spin relaxation times have been determined by means of measured time dependent intensity and polarization of electron emission. We also performed theoretical calculations of photocathode pulse response and compared the obtained results with experimental data. Our analysis testifies the presence of partial electron localization in SL. Electron capture by localized states leads to unavoidable losses of quantum efficiency and polarization.

[en] Optimized AlInGaAs/AlGaAs superlattice with strained quantum wells has been developed, fabricated and studied. The choice of hetero-layer composition and thicknesses is based on calculations of Sl's band energy spectrum, photoabsorption spectrum and transport properties. Electron emission from the developed photocathodes demonstrates maximal polarization above 90%.

[en] The fluctuations and dynamic characteristics of an Nd:YAG monolithic ring laser with a nonplanar configuration of the cavity placed in a magnetic field were investigated experimentally and theoretically. A vector model of a solid-state ring laser was developed. It takes into account the characteristic features of the interaction of elliptically polarised counterpropagating waves in an anisotropic cavity and is consistent with experimental results. (lasers)

[en] Photoemission of polarized electrons from heterostructures based on InAlGaAs/GaAs superlattices with minimum conduction-band offsets is investigated. The comparison of the excitation energy dependence of the photoemission polarization degree with the calculated spectra make it possible to determine the polarization losses at different stages of the photoemission. A maximum polarization of P = 91% and a quantum yield of 0.14% are close to the best results obtained for photocathodes on the basis of strained semiconductor superlattices

[en] The transport of polarized electrons in photocathodes based on highly strained semiconductor superlattices is studied experimentally and theoretically. In the experiments, the electron emission from the photocathode excited by a femtosecond laser pulse is studied by time-resolved measurements. The response time and the spin relaxation time are experimentally determined. The photoresponse of the photocathodes is calculated, and the results are correlated with the experimental data. A conclusion regarding the partial localization of photoelectrons in the superlattice is drawn.

[en] The paper proposes a new approved system for control and monitoring of the working process parameters during production of building ceramic bricks for modern enterprises. We analyzed various devices for measuring the raw brick temperature, and identified the shortcomings of the existing instruments and measuring systems. To create high production efficiency, increase the competitiveness of products on the market, reduce the product cost as part of automation of long-term and energy-intensive technological processes, we proposed a method of organizing optimal control of drying process of ceramic bricks at the industrial plant using new Celsius © thermal sensors. A digital temperature sensor is used as a sensitive element, which eliminates the need for calibrating the primary transducer. The device can be installed on the object of examination using a threaded connection, magnetic mounting, or can be used to measure the temperature at the required depth due to remote primary measuring transducer. It is shown that device is universal and will be efficient for the needs of enterprises for which the control of thermodynamic parameters is the basis of the technological process. (paper)