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Author (up) Nikoghosyan, A. S.; Martirosyan, R. M.; Hakhoumian, A. A.; Makaryan, A. H.; Tadevosyan, V. R.; Goltsman, G. N.; Antipov, S. V.
Title Effect of absorption on the efficiency of THz radiation generation in a nonlinear crystal placed into a waveguide Type Journal Article
Year 2018 Publication Armenian J. Phys. Abbreviated Journal Armenian J. Phys.
Volume 11 Issue 4 Pages 257-262
Keywords THz, waveguide, nonlinear crystal
Abstract The effect of THz radiation absorption on the efficiency of generation of coherent THz radiation in a nonlinear optical crystal placed into a metal rectangular waveguide is studied. The efficiency of the nonlinear conversion of optical laser radiation to the THz band is also a function of the phase-matching (PM) condition inside the nonlinear crystal. The method of partial filling of a metal waveguide with a nonlinear optical crystal is used to ensure phase matching. Phase matching was obtained by the proper choice of the thickness of the nonlinear crystal, namely the degree of partial filling of the waveguide. We have studied the THz radiation attenuation caused by the losses in both the metal walls of the waveguide and in the crystal, taking into account the dimension of the cross section of the waveguide, the degree of partial filling and its dielectric constant.
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Corporate Author Thesis
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1829-1171 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1291
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Author (up) Prokhodtsov, A.; An, P.; Kovalyuk, V.; Zubkova, E.; Golikov, A.; Korneev, A.; Ferrari, S.; Pernice, W.; Goltsman, G.
Title Optimization of on-chip photonic delay lines for telecom wavelengths Type Conference Article
Year 2018 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume 1124 Issue Pages 051052
Keywords optical delay lines
Abstract In this work, we experimentally studied optical delay lines on silicon nitride platform for telecomm wavelength (1550 nm). We modeled the group delay time and fabricated spiral optical delay lines with different waveguide widths and radii as well as measured their transmission. For the half etched rib waveguides we achieved the losses in the range of 3 dB/cm.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1196
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Author (up) Romanov, N. R.; Zolotov, P. I.; Vakhtomin, Y. B.; Divochiy, A. V.; Smirnov, K. V.
Title Electron diffusivity measurements of VN superconducting single-photon detectors Type Conference Article
Year 2018 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume 1124 Issue Pages 051032
Keywords SSPD, SNSPD, VN
Abstract The research of ultrathin vanadium nitride (VN) films as a promising candidate for superconducting single-photon detectors (SSPD) is presented. The electron diffusivity measurements are performed for such devices. Devices that were fabricated out from 9.9 nm films had diffusivity coefficient of 0.41 cm2/s and from 5.4 nm – 0.54 cm2/s. Obtained values are similar to other typical SSPD materials. The diffusivity that increases along with decreasing of the film thickness is expected to allow fabrication of the devices with improved characteristics. Fabricated VN SSPDs showed prominent single-photon response in the range 0.9-1.55 µm.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1742-6588 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1229
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Author (up) Shurakov, A.; Mikhalev, P.; Mikhailov, D.; Mityashkin, V.; Tretyakov, I.; Kardakova, A.; Belikov, I.; Kaurova, N.; Voronov, B.; Vasil’evskii, I.; Gol’tsman, G.
Title Ti/Au/n-GaAs planar Schottky diode with a moderately Si-doped matching sublayer Type Journal Article
Year 2018 Publication Microelectronic Engineering Abbreviated Journal Microelectronic Engineering
Volume 195 Issue Pages 26-31
Keywords
Abstract In this paper, we report on the results of the study of the Ti/Au/n-GaAs planar Schottky diodes (PSD) intended for the wideband detection of terahertz radiation. The two types of the PSD devices were compared having either the dual n/n+ silicon dopant profile or the triple one with a moderately doped matching sublayer inserted. All the diodes demonstrated no noticeable temperature dependence of ideality factors and barrier heights, whose values covered the ranges of 1.15–1.50 and 0.75–0.85 eV, respectively. We observed the lowering of the flat band barrier height of ∼80 meV after introducing the matching sublayer into the GaAs sandwich. For both the devices types, the series resistance value as low as 20 Ω was obtained. To extract the total parasitic capacitance, we performed the Y-parameters analysis within the electromagnetic modeling of the PSD's behavior via the finite-element method. The capacitance values of 12–12.2 fF were obtained and further verified by measuring the diodes' response voltages in the frequency range of 400–480 GHz. We also calculated the AC current density distribution within the layered structures similar to those being experimentally studied. It was demonstrated that insertion of the moderately Si-doped matching sublayer might be beneficial for implementation of a PSD intended for the operation within the ‘super-THz’ frequency range.
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Language Summary Language Original Title
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Series Volume Series Issue Edition
ISSN 0167-9317 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1155
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Author (up) Sidorova, M. V.; Kozorezov, A. G.; Semenov, A. V.; Korneev, A. A.; Chulkova, G. M.; Korneeva, Y. P.; Mikhailov, M. Y.; Devizenko, A. Y.; Goltsman, G. N.
Title Non-bolometric bottleneck in electron-phonon relaxation in ultra-thin WSi film Type Miscellaneous
Year 2018 Publication arXiv Abbreviated Journal
Volume Issue Pages
Keywords WSi films, diffusion constant, SSPD, SNSPD
Abstract We developed the model of the internal phonon bottleneck to describe the energy exchange between the acoustically soft ultrathin metal film and acoustically rigid substrate. Discriminating phonons in the film into two groups, escaping and nonescaping, we show that electrons and nonescaping phonons may form a unified subsystem, which is cooled down only due to interactions with escaping phonons, either due to direct phonon conversion or indirect sequential interaction with an electronic system. Using an amplitude-modulated absorption of the sub-THz radiation technique, we studied electron-phonon relaxation in ultrathin disordered films of tungsten silicide. We found an experimental proof of the internal phonon bottleneck. The experiment and simulation based on the proposed model agree well, resulting in tau{e-ph} = 140-190 ps at TC = 3.4 K, supporting the results of earlier measurements by independent techniques.
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Notes Duplicated as 1305 Approved no
Call Number Serial 1341
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