Vera D. Vinokurova

Spatial and temporal structures in cavities with oscillating boundaries

We review the general features of particles, waves and solitons in dynamical cavities formed by oscillating cavity mirrors. Considered are the dynamics of classical particles in one-dimensional geometry of a dynamical billiard, taking into account the non-elastic collisions of particles with mirrors, the (quasi-energy) states of a single quantum particle in a potential well with periodically oscillating wells, and nonlinear structures, including nonlinear Rabi oscillations, cavity optical solitons and solitons of Bose–Einstein condensates, in dynamical cavities or traps.

Holographic diffraction gratings with multilayer insulator coatings

Based on numerical modeling of metallized diffraction gratings with multilayer insulator coatings, the diffraction efficiency of such gratings is investigated, assuming that the initial profile of the metallized grat-ing is not reproduced in the course of sequential deposition of coating layers. From comparison of experimental and calculated data, it is concluded that the initial grating relief is subject to considerable smoothing. The new nontraditional range of the optimum values of layer thicknesses, which provides a high diffraction efficiency in the operating wavelength range of 1.06 μm, is suggested. The stability of the diffraction efficiency with respect to random errors in the thickness of insulator layers deposited is investigated numerically.

Dynamic billiards for particles with inelastic reflections

The one-dimensional dynamics of particles that move between a stationary and a harmonically oscillating mirror have been analyzed analytically and numerically taking into account inelastic collisions of particles with mirrors. It has been shown that, in such “billiards,” in contrast to the case of elastic collisions, asymptotically stable periodic regimes are established, including the regime of periodic sticking of a particle to the oscillating mirror, as well as regimes of dynamic chaos.

Calculation and optimization of parameters of deep groove gratings with multilayer dielectric coating for compression of high-power laser pulses

The method of calculating the electromagnetic wave field diffracted by a holographic grating with a multilayer dielectric coating is developed. The method consists of the representation of the field inside dielectric layers in the form of a plane-wave expansion for weakly damped harmonics and an expansion over functions of the concomitant coordinate system for strongly damped orders. This modification of the method allows calculation of the diffraction efficiency and the electric field strength for the deep groove gratings. It is shown that a diffraction element that possess high efficiency and radiation strength can be obtained even when the profile of the dielectric layers flattens with an increase in the distance from the grating’s metallic layer.

Comparative analysis of diffraction gratings for femtosecond pulse compression systems based on numerical simulation of their parameters

The parameters of diffraction gratings that can be used to compress high-power femtosecond pulses of neodymium glass lasers are analyzed based on numerical calculations. The parameters of gratings of different types are compared to evaluate prospects for their use.

On the effect of nonequidistance of dielectric coatings and the groove profile on the energy characteristics of holographic diffraction gratings

The diffraction efficiency and the resistance to radiation damage of gratings with a multilayer dielectric coating, which are used for compression of high-power laser pulses, are studied. The effect of smoothing of the profile of the metallized surface of the grating upon deposition of dielectric coatings on the energy characteristics of the grating at the wavelength λ=1.05 μm is analyzed. Gratings with various profiles of the metallic surface relief and with different contrast of the refractive indices of the dielectrics forming the coating are considered.

Diffraction efficiency and damage threshold of the holographic grating with a multilayer dielectric coating

In the process of creation of multi-layered coating through evaporation of the dielectric occurs considerable smoothing of an initial grating relief. The smoothing results in reduce of the diffraction efficiency and damage threshold of the grating at the working wavelength. The value of the smoothing is measured. Calculation of the structure parameters of the grating by real smoothing is made to improve the diffraction efficiency and damage threshold.

Computer simulation of generation and propagation of ultrashort high-power laser pulses in optical systems

We performed computer simulation of the amplifier tract of a terawatt picosecond laser with pulse compression by means of our 3-D computer code PIKA. Parameters of the laser system on Nd-glass for obtaining subpicosecond pulses were determined. Our computer code VERA was used for simulation of a compressor based on holographic metallized gratings with dielectric coating and increased damage threshold.