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This paper reports on theoretical and experimental studies of a new class of zero-order diffractive elements — diffractive light attenuators with variable transmission. Results of tests of circular diffractive attenuators for wavelengths of 532 and 1064 nm with amplitude and phase transmission functions are presented. Methods of fabrication of the attenuators are discussed, and the characteristics of prototype modles are considered. It is shown that phase attenuators in the form of embossed circular diffractive gratings with a period of 2 to 6 µm and a variable duty cycle are not selective to polarization and allow controlling the radiation power of pulsed (including femtosecond) and continuous lasers over a wide range (> 100 times)

A microbeam X-ray lithography apparatus, a new device for the direct production of microstructures in thick layers of X-ray resists, in particular, for the fabrication of X-ray lithography masks, was developed on the basis at the LIGA station of the VEPP-3 storage ring of the Siberian Center of Synchrotron and Terahertz Radiation. A microstructure pattern with given arbitrary topology was produced directly in a SU-8 negative resist layer up to 1 mm thick on a substrate moved in a vector mode using a collimated beam of synchrotron radiation with a special software. The design of the device and its technological capabilities and limitations are described. Examples of the fabricated microstructures with a high aspect ratio and X-ray lithography masks are presented

It is predicted theoretically that the combination of elliptically polarized radiation and an antirelaxation coating of the walls of a vacuum cell containing alkali metal vapor provides an asymmetric shape of the magneto-optical resonance. The cause of the asymmetry is the optical pumping of the ground-state hyperfine component which is not destroyed upon collision of the atom with the wall. The effect is most pronounced when the laser frequency is tuned to the resonance with the the F → F + 1 transition

Results of the research aimed at improving the strength of hybrid photodetectors (PD) based on mercury—cadmium—telluride heteroepitaxial layers are presented. It is shown that annealing of silicon multiplexers at 157 ºC in a hydrogen flow in vacuum changes the shape of indium bumps to hemispherical and levels off their mechanical properties over the plate. Controlled recovery of the natural curvature of silicon multiplexer plates and photosensitive element arrays in hybrid photodetectors at 120 ºC extends their operation time. A sequence of technological operations on PD hybridization providing an increase in the efforts needed for separating photosensitive elements from silicon multiplexers at least by 75 % compared to the PD with fused indium bumps is proposed

Results of numerical 2D and 3D-simulations of the performance of nanowire sensors on the basis of silicon-on-insulator structures aimed at determining the optimum conditions for the response to dielectric particles, are given. The effect of screening of nanowires by dielectric particles in solutions with pH = 7 used as a medium for transporting biological objects is considered

Various approaches to solving the problem of filtration of a continuous periodic signal distorted by stationary additive non-correlated noise are considered. Particular attention is paid to the case where the known signal period is non-divisible by the signal sampling period.

Two methods of statistical estimation of the optimal regularization parameter of a nonlinear algorithm for signal recovery are proposed, one of which is based on the optimality criterion and the other one on the residual principle. These methods have simple algorithmic implementation and do not need a priori information about the quantitative characteristics of the sought solution. The results of numerical experiments show the effectiveness of the method based on the optimality criterion.

The effect of reduction of the signal sampling frequency by the signal mean value in the case of superposition of a harmonic noise component onto the original steady stochastic signal is studied. Conditions under which reduction of the observation frequency of this process significantly changes the observed mean values are found. In this regard, a number of statements are formulated and proved. The consequences of a reduction of the observation frequency of the dynamometer signal for the experiment performed in an ice basin with a tanker hull model are considered.

An approach to 3D image processing based on the modified generalized Hough transform is proposed. The possibility of processing images with unknown rotation and scaling parameters and images represented by individual fragments of the original image is shown. The efficiency of the proposed algorithms for solving problems of 3D image recognition is studied.

This paper presents an algorithm for determining the coordinates of small objects appearing in a sequence of scene images based on sum and difference processing of the detailing wavelet coefficients of the current and reference images, followed by a morphological analysis of the generated pseudo-image. The effectiveness of the algorithm is compared with the difference algorithm for analyzing changes in the observation scene. It is shown that the proposed algorithm is more resistant to the effects of relative shifts of the current and reference images.