Vol 17, No 5 (2023)

13 июля в Екатеринбурге завершилась 13-я Международная промышленная выставка ИННОПРОМ. Главная тема выставки – «Устойчивое производство: стратегии обновления». Основные разделы выставки: цифровое производство, транспортное машиностроение, металлообработка, технологии для энергетики, производство компонентов, новые материалы, автоматизация и робототехника, информационно-коммуникационные технологии, медицинское оборудование и фармацевтика, технологии для городов. Представлен краткий обзор мероприятий деловой программы, в которых приняли участие обозреватели журнала ФОТОНИКА.

The design of an optical system for focusing a laser beam with an extremely small spot size in a wide range of distances from 50 m to 2 km is presented. Difficulties with controlling the laser beam and focusing it are reduced by using a circuit with a laser beam expander.

The possible application of crystals from the sillenite group (Bi₁₂SiO₂₀, Bi₁₂GeO₂₀, Bi₁₂TiO₂₀) to detect radiation in the terahertz (near infrared) range is considered. Photosensitivity for the spectral range of 3–30 μm is provided by application of the shallow traps located near the bottom of the conduction band. The crystal sections are determined, at which the electro-optical and piezoelectric effects can be used to develop a voltage on the surface electrodes. The electrodes made in the form of an interdigital transducer or a spiral complement the device with new functional capabilities.

The up-to-date tools, instruments and measurement methods for the optically transparent materials in a wide spectral range (from ultraviolet to terahertz) are presented. Particular attention is paid to the terahertz range, a relatively new area in optics being at the interface with radiophysics.

The paper presents the study results of the effect of a biconical axicon, a refractive optical element with two conical surfaces, on illumination by radiation of various polarization states, including inhomogeneous one (with azimuthal and radial polarization). The biconical axicon was previously proposed for converting a beam with circular polarization into a azimuthal polarized beam due to the beam reflection and refraction at the Brewster angle on one conical surface, followed by the beam collimation due to the second conical surface. The polarization transformations performed during diffraction of beams with various polarizations by a biconical axicon are calculated using the finite difference method in the time domain. Based on the numerical simulations, it is shown that the biconical axicon made of K14 glass (with the refractive index n = 1.4958) can be used as a detector for azimuthal and radially polarized beams based on the intensity pattern in one plane.

The estimation method for the spatial radiation structures of unmanned aerial vehicles is proposed that allows obtaining the approximate mathematical models of their spatial radiation structure. Such models can be used as the initial data for efficiency evaluation of problem solution related to the detection of unmanned aerial vehicles using the passive optoelectronic systems.

The comparative analysis results of the influence of the optic specifications of irradiation devices with different designs on the plant growth and yield (Mewa F1 cucumbers) are given. The design of LED lamps has been optimized, and a lighting engineering model has been prepared to make a laboratory bench for studying the optical radiation effect on the plant growing process in the greenhouse conditions. The experimental prototypes of irradiation devices based on the LEDs have been prepared that ensure the plant performance with a smaller stem growth.