Study of influence of external signal on the dynamic of low-voltage system based on helical electron beams with virtual cathode
Study of influence of external signal on the dynamic of low-voltage system based on helical electron beams with virtual cathode
E. N. Egorov$^1$, A. G. Petrik$^2$, A. E. Hramov$^{1,2}$
The study of influence of external harmonic signal on generation in low-voltage vircator with magnetron-injection gun as source of electron beam are carried out. The classical phenomenon of synchronization in the distributed electron-wave system are observed. The possibility of vircator output signal power increasing with the frequency of external signal changing are shown.
Show AbstractLow-energy spin systems based on the Bernasconi model
Low-energy spin systems based on the Bernasconi model
A. N. Leukhin$^1$, V. I. Bezrodnyy$^1$, N. A. Kokovihina$^1$
A method of constructing a low-level quantum system for a one-dimensional spin lattice consisting of N particles is proposed. In the Bernasconi model, the problem of constructing the simplest quantum system in the form of a one-dimensional Ising model reduces to the problem of constructing binary sequences with the lowest side-lobe energy. In this paper, we provide a computationally effective method of exhaustive search for binary sequences with a low level of side lobes. Examples of low-level one-dimensional spin lattices of record lengths N > 80 are synthesized and presented
Show AbstractTwo-dimensional single-channel and multichannel optically induced waveguide structures formed in a lithium niobate crystal with the pyroelectric effect
Two-dimensional single-channel and multichannel optically induced waveguide structures formed in a lithium niobate crystal with the pyroelectric effect
A. S. Perin, T. L. Grigoryan, B. M. Budaev, V. M. Shandarov
Formation of single two-dimensional waveguides and multi-element (3 and 5 waveguides) of such waveguides within a bulk of undoped lithium niobate has been experimentally demonstarated. Waveguide structures with a channel size of 8, 12, 23 μm have been formed by the bright spatial solitons obtained at the compensation of the diffraction divergence of light beams in the crystal due to the contribution of the pyroelectric effect into the nonlinear response. The light wavelength were 532 and 633 nm and the optical power was ranged from 50 to 200 μW in experiments. The total compensation of the diffraction divergence at uniform heating of the crystal sample to the temperature from 35 to 55 degrees Celsius.
Show AbstractPolyphase sequences of long lengths with low level of sidelobes of aperiodic autocorrelation function
Polyphase sequences of long lengths with low level of sidelobes of aperiodic autocorrelation function
A. N. Leukhin$^1$, V. I. Bezrodnyy$^1$, N. A. Kokovihina$^1$
The numbered iteration algorithm for polyphase sequence constructions with low level sidelobes of aperiodic autocorrelation function is offered. The example of polyphase sequence for the length N = 512 with peak sidelobe of aperiodic autocorrelation function with PSL = 1.763 is demonstrated. Polyphase sequences with a low level of side lobes AACF are widely used as modulating signals in radar systems for various purposes. A low level of side lobes provides detection of targets with a low effective scattering area (ESA) against the background of high ESA targets.
Show AbstractREGIMES OF DEVEPOLED CHAOS IN GYROTRONS AND GYRO-AMPILIFIERS WITH DELAYED FEEDBACK
REGIMES OF DEVEPOLED CHAOS IN GYROTRONS AND GYRO-AMPILIFIERS WITH DELAYED FEEDBACK
R. M. Rozental$^1$, N. S. Ginzburg$^1$, I. V. Zotova$^1$, O. B. Isaeva$^{2,3}$, A. G. Rozhnev$^{2,3}$, A. S. Sergeev$^1$
The characteristics of output radiation of gyro-amplifiers (such as gyroklystron and helical waveguide gyro-TWT) with delayed feedback and gyrotron, operated at the regime of high exceeding of the threshold, were studied. It was shown, that this devices could produce wideband chaotic oscillations with a relative spectrum width up to 10% at the millimeter wavelength. In all cases these regimes are referred to as hyperchaos.
Show AbstractDynamics of a multilayer adaptive network with cooperative interaction between layers
Dynamics of a multilayer adaptive network with cooperative interaction between layers
D. V. Kirsanov$^1$, V. V. Makarov$^1$, M. V. Goremyko$^1$, V. O. Nedajvozov$^1$, A. E. Hramov$^1$
In this paper, we investigated the processes of synchronization and the formation of structural patterns in a multilayered network of dynamic elements. The layers compete for an optimal topology, where elements interactions within the layer occurs according to the principles of additivity and homeostasis.
Show AbstractFormation of clusters in a complex network reflecting the process of cooperation in social groups
Formation of clusters in a complex network reflecting the process of cooperation in social groups
V. O. Nedajvozov$^1$, V. V. Makarov$^1$, M. V. Goremyko$^1$, D. V. Kirsanov$^1$
In this study, we investigated the processes of clustering in multilayered social networks of collaborations and professional interactions. We have identified the basic principles that are responsible for the interconnection of topology and dynamic characteristics in such kind of networks.
Show AbstractCalculation of high-efficiency resonators of solid-state lasers
Calculation of high-efficiency resonators of solid-state lasers
P. A. Nosov
The problem of calculating the stable resonators of solid-state lasers forming a Gaussian beam with variable spatial parameters (waist diameter, confocal parameter, angular divergence) with the energy parameters of the radiation unchanged is considered. The scheme of the optical system of a resonator of a solid-state laser to solve this task is presented. By the ray bundle method and on the base of scalar diffraction theory, the problem of calculating the characteristics of a laser beam formed by linear resonators of arbitrary configuration taking into account the aberrations of its elements is considered. The results of modeling the mirror-lens resonator scheme for varying the spatial parameters of the output beam by the ray bundle method are presented. For stable resonators approximate analytical expressions are obtained, which allow to calculate the distribution of the complex amplitude on mirrors and in an arbitrary cross section of the resonator, the spatial parameters of beam and the frequency spectrum of the radiation for a rectangular and circular aperture of mirrors. The configurations of resonators in which the aberrations of the shape of the surface of mirrors have a significant effect on the characteristics of the formed laser radiation are determined.
Show AbstractCalculation of the optical system for process equipment on the basis of high-power fiber laser
Calculation of the optical system for process equipment on the basis of high-power fiber laser
P. A. Nosov, А. O. Shchadko
Features of functioning of optical systems of the process equipment on the basis of powerful fiber lasers are considered. The experimental results show that the distribution of the power density of the laser radiation and the temperature distribution on the optical element of the laser head can be approximated by the Gaussian function. The results of experimental studies of the heating of optical elements from high-purity quartz glass of the Russian production of the grade KS-4V are presented in the formation of radiation from a CW high-power fiber laser. The maximum heating temperature of optical elements at various laser power densities are determined. Expressions are given for analyzing the thermal-optical distortions of the beam at the output of the optical system of laser equipment for technological processes of material processing. Analysis of the optical systems calculated has shown that when heating of lenses made of quartz glass under the influence of high-power laser radiation, the output waist is shifted closer to the protective glass, and its diameter remains practically unchanged. The researches show that when designing of laser optics for the modern technological equipment on the basis of powerful fiber lasers the account of heating of lenses is very important.
Show AbstractThe temperature dependence features of the spectral characteristic of a diode laser with a frequency doubler
The temperature dependence features of the spectral characteristic of a diode laser with a frequency doubler
V. V. Bliznyuk$^2$, O. I. Koval$^2$, V. P. Alekseevich$^2$, A. G. Rzhanov$^1$, A. E. Tarasov$^2$
It was experimentally found that when the ambient temperature changes from 260 K to 345 K, the peak wavelength of the spectral characteristic of a laser diode with a frequency doubler on a KTP crystal is practically not shifted relative to the position it occupied at room temperature. The justification of this phenomenon is given.
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