Direct Metal Deposition of Titanium-based Cermets DOI: 10.22184/1993-7296.FRos.2021.15.4.296.306
The results of experimental studies of the macro- and microstructure, chemical and phase composition of a cermet alloy based on titanium are presented. The material is intended for laser methods of additive manufacturing using direct metal deposition. For analysis, samples were obtained with a ceramic powder content of 5 and 10 vol. % SiC. The introduction of ceramic particles turned out to be effective for refining the alloy grains. The grain size of pure titanium is about 3.5 mm, while the grain size of titanium reinforced with silicon carbide at a radiation power of 1400 W was 50 and 14 μm for 5 and 10% SiC, respectively. As a result of the introduction of ceramic particles into the titanium matrix, the microhardness of the composite material increases, the hardening increases, but the embrittlement of the material also increases due to the violation of the integrity of the material and the occurrence of a reaction at the phase boundary.
Exposure of a Transparent Material with a Laser Radiation Band Gap with a Wavelength from the Spectral Region of the Absorption Edge DOI: 10.22184/1993-7296.FRos.2021.15.4.308.315
This work is a fundamental study of the process of motion of the heating region towards laser radiation during laser pulsed modification of the transparent materials structure. Numerical estimates of the magnitude of thermomechanical stresses in the material (2–3 GPa) are given. This significantly exceeds the elastic limit of semiconductor materials (40–100 MPa). A mechanism for the formation of linear tracks of microcracks directed from the focusing region of the laser pulse to the surface of the material is proposed. As a result, the effect of blocking the temperature rise in the focal region arises during the remaining pulse duration.
The choice of the energy and time parameters of the laser pulse, the geometrical position of the focus makes it possible to implement two types of changes in the material structure: spot or extensional. An experimental confirmation of this possibility has been obtained for monocrystalline semiconducting zinc selenide. Both types of structural changes can be used to solve a wide range of practical problems.
Comprehensive Assessment of the Operational Reliability of a Modular Cabin With Laser Radiation Active Protection DOI: 10.22184/1993-7296.FRos.2021.15.4.282.295
The results of a comprehensive assessment of the operational reliability of a modular cabin with active protection against the effects of laser radiation are presented. The work was carried out in two stages. At the initial stage, a computational and experimental two-level technique was developed and implemented in practice, including, at the first level, determining the response time of the emergency protection system against laser radiation in a modular cabin with a continuous laser generator with a fiber optic system operating with a maximum power of 6 kW. At the second level, the stress state and bearing capacity of the elements of the modular cabin were assessed. The advantages of a modular cabin in terms of equipping with protection means are shown over protective cabins of a conventional (without active protection) design. At the final stage, after two-level studies, the reliability of the protection of the modular cabin from reflected and scattered radiation during laser technological processes was assessed.
Visible and Near Infrared Spectrometers for Scientific and Industrial Applications DOI: 10.22184/1993-7296.FRos.2021.15.4.316.322
Spectrometers of the visible and near-IR ranges, designed for recording the spectral characteristics of samples of different nature, are presented. The device is based on the optical scheme of Czerny-Turner, rifled diffraction gratings are used. Spectrometers can be used as a separate module in spectrophotometers, spectrofluorometers, Raman spectrometers. The design of the device is based on high adaptation to specific tasks of industrial and scientific applications.
Modern Microwave Photonics in Russia: Report From the Scientific-Practical Conference “Microwave Photonics” in the Framework of the Congress of the Photonics Russian Technological Platform DOI: 10.22184/1993-7296.FRos.2021.15.4.324.332
The XV International specialized exhibition of laser, optical and optoelectronic equipment “Photonics. World of Lasers and Optics” took part from March 30 till April 2. The exhibition became an anniversary in 2021. Unfortunately, the exhibition was canceled in 2020 due to the pandemic. Traditionally, this is important event for the high-tech industry in the field of photonics, optics and laser technologies, where manufacturers of specialized equipment and optical components from different countries are represented. Also meetings of thematic sections of an extensive business program are held, at which speakers from leading Russian research and production enterprises present the advanced results of their activities.
Principles of Constructing Optoelectronic Microwave Oscillators. Part II DOI: 10.22184/1993-7296.FRos.2021.15.4.334.346
The article confronts the readers with the principles of creating optoelectronic microwave generators. The physical processes underlying the operation of various types of oscillators are briefly considered in the first part of the review (see PHOTONICS RUSSIA. 2021; 15(3):228–237. DOI: 10.22184/1993-7296.FRos.2021.15.3.228.237). Optoelectronic microwave generators based on active ring resonant systems and a comparison of the phase noise of different types of optoelectronic generators are considered in the second part of the review.
Will Quantum Computers Replace Classic and is There an Alternative to Parallel Computers? DOI: 10.22184/1993-7296.FRos.2021.15.4.348.351
Will Quantum Computers Replace Classic, and is There an Alternative to Parallel Computers?
One of the most dynamically developing areas of technology has become modern quantum technologies, the main areas of development of which are: quantum information processing, quantum cryptography, quantum metrology and quantum sensorics. The mature quantum applications markets (optical fibers, lasers, magnetic resonance imaging (MRI) and GPS devices) are large, established markets of around US $ 100 billion with attractive growth rates of ~ 10%. But let’s move away from these markets towards the expected breakthrough in the creation of quantum computers.