Vol 18, No 7 (2024)

In the continuation of the review, the properties of metamaterials are considered, and an analysis of publications that indicate the possibility of low–field emission of various semiconductor and polymer materials at the size of nanogreens or points 20–30 nm is carried out. We will show that for the manufacture of a source of high-energy seed fast electrons and the realization of breakdown on escaping electrons, it is sufficient to use a thread 30–50 m long with fractals of aluminum nanostructures (nanodrops) with a size of 10–30 nm.

The optimization results of the generation technology for the modified absorption silicon surfaces are provided that allows to improve the spectral characteristics of devices obtained on its basis: radiation cooling devices, IR sources and sensors.

This paper is devoted to the study of luminescent properties of porous silicon doped with erbium. The development of semiconductor materials activated by the lanthanides is a vital task of contemporary physics and technology of optoelectronic devices. The object of research is oxidized porous silicon doped with the erbium ions. The structural and morphological analysis and study of the luminescent properties of luminescent structure samples based on the porous silicon doped with erbium have been performed. The studies have been carried out by the methods of scanning electron microscopy, Raman spectroscopy and micro-photoluminescence spectroscopy. The analysis of samples has demonstrated a correlation between the process parameters of the produced luminescent structures and efficiency of their photoluminescence. The results of studies can be used as a basis for the production method of silicon luminescent structures for optoelectronics.

The article analyzes the structural, stress condition and triboengineering tests of 65G steel samples after the laser and conventional hardening methods for possible extension of the service life of parts and mechanisms for the forestry and agricultural machinery. It is established that the abrasive wear resistance is increased by 2.5 and 1.7 times compared to 65G steel in the initial condition and after bulk hardening, respectively. Based on the experimental assessment results of the thermal residual stress level after the bulk furnace hardening and laser hardening of the 65G steel samples, a calculation has been made for the predicted subsequent service life of the parts of tilling mechanisms and machines.

The design and analysis of the optical circuit for the wide-angle oculars for an immersion multifocal head-mounted display are given. The ocular is based on the use of a beam-splitting cube as a splitter to generate two image planes. The field-of-vision angle is 44°×33°, 60° diagonally. The maximum radius of the circle of confusion (RMS radius) is 13.2 µm, with a pixel size of 9.3 µm.

The paper shows that when linearly polarized laser radiation of red (633 nm), green (526 nm), and blue (405 nm) ranges passes through the leaves of maize plants, the ellipticity of polarization changes depending on the angle of rotation of the sample. The largest changes in ellipticity occur when passing blue light, for which the ellipticity index k varies from –16° to 16°. When red and green light passes through the sample, the ellipticity varies from –9° to 10° and –9° to 8°, respectively. It is suggested that these variations are due to the interaction of light with the epidermis layer. The layer cells are ordered and have shape of rectangles with wavy edges, which leads to the refractive index anisotropy and the phase shift between the two orthogonal components of the E vector. The interaction of light with greater ellipticity with chiral photosensitive structures should occur more efficiently, thus, allegedly, this is the plants mechanism to use linearly polarized light.