Channel Optical Waveguides with Spatial Longitudinal Modulation of Their Parameters Induced in Photorefractive Lithium Niobate Samples

The influence of point-by-point exposure of lithium niobate sample surface, doped with photorefractive impurities, to the longitudinal modulation of refractive index inside the formed waveguide channel is experimentally studied using optical probing method. Formation of channel waveguides by laser beam in different directions with respect to the crystal optical axis has been demonstrated. The channel waveguides have been formed via the point-by-point exposure at light wavelengths of 532 nm and 450 nm. Variation of distance between exposing light spot centres demonstrates the possibilities of optical inducing of longitudinally homogeneous and inhomogeneous channel waveguides

Dynamics of Changes in Optical Absorption Induced By Nanosecond Laser Pulses in the Bi12Tio20:Al Crystal

The dynamics of the changes in optical absorption in Bi12TiO20:Al crystal at the wavelength of 655 nm, which were induced by a packet of laser pulses with the wavelength of 526.5 nm, pulse width of 10 ns, repetition frequency from 10 Hz to 1 kHz and pulse energy of 9-15 μJ had been experimentally investigated. Keywords: light-induced absorption, bismuth titanium oxide crystal, impulse radiatio

Dark photovoltaic spatial solitons in a planar waveguide obtained by proton implantation in lithium niobate

Abstract. A photovoltaic dark spatial soliton is generated in a planar waveguide produced by the implantation of protons into a copper-doped lithium niobate crystal. Stationary soliton regimes are achieved at powers 90 and 30 lW at wavelengths 633 and 532 nm, respectively

The power supply system model of the process submersible device with AC power transmission over the cable-rope

A practical problem of power supply system modeling for the process submersible device with AC power transmission over the cable-rope was considered. The problem is highly relevant in developing and operation of submersible centrifugal pumps and submersibles. The results of modeling a symmetrical three-phase power supply system and their compliance with the real data are given at the paper. The obtained results in the mathematical and simulation models were similar

Light diffraction on periodically poled domain structures in lithium niobate crystal in an sunusoidal voltage

This study was carried out with the financial support of Ministry of Education and Science of Russia (within the task No. 3.1110.2017/4.6 of the project part) and RFBR (Grant 16-29-14046-ofi_m). The equipment of the Ural Center for Shared Use “Modern Nanotechnology” UrFU has been used

Mathematical model for the power supply system of an autonomous object with an AC power transmission over a cable rope

A modeling problem of the power system, which provides an AC power transmission to a submersible device over the conducting rope, was considered. The power supply system units and their parameters are described. The system multi-dimensional mathematical model in the variables state space with regard to the nonlinear characteristic of system elements is proposed

Methods for controlling of the laser-induced absorption in a BTO crystal by using of cw-laser radiation

A photorefractive BTO crystal is exposed with cw-laser beams (430 mW/cm2 at 514 nm), and the photoinduced absorption between 480 and 900 nm is studied. A method of controlling this absorption by low intensity laser radiation of “green” and “red” wavelengths is demonstrated. The physical mechanism can be explained by the redistribution of electrons on the long-lived energy levels into the forbidden band. Dynamical characteristics of the redistribution are estimated

Diffraction methods of investigation of the periodical domain structures with inclined domain walls in lithium niobate

This work was supported by the Russian Foundation for Basic Research (Grant No 16-29-14046-ofi_m) and by the Ministry of Science and Higher Education of the Russian Federation for 2017- 2019 (State Tasks No 3.1110.2017/4.6 and 3.8898.2017/8.9)