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Author Iomdina, E. N.; Seliverstov, S. V.; Teplyakova, K. O.; Jani, E. V.; Pozdniakova, V. V.; Polyakova, O. N.; Goltsman, G. N.
Title Terahertz scanning of the rabbit cornea with experimental UVB-induced damage: in vivo assessment of hydration and its verification Type Journal Article
Year 2021 Publication J. Biomed. Opt. Abbreviated Journal J. Biomed. Opt.
Volume 26 Issue 4 Pages
Keywords (up) medicine; scheimpflug imaging; UVB; confocal microscopy; cornea; optical coherent tomography; rabbit eyes; terahertz radiation
Abstract SIGNIFICANCE: Water content plays a vital role in the normally functioning visual system; even a minor disruption in the water balance may be harmful. Today, no direct method exists for corneal hydration assessment, while it could be instrumental in early diagnosis and control of a variety of eye diseases. The use of terahertz (THz) radiation, which is highly sensitive to water content, appears to be very promising. AIM: To find out how THz scanning parameters of corneal tissue measured by an experimental setup, specially developed for in vivo contactless estimations of corneal reflectivity coefficient (RC), are related to pathological changes in the cornea caused by B-band ultraviolet (UVB) exposure. APPROACH: The setup was tested on rabbit eyes in vivo. Prior to the course of UVB irradiation and 1, 5, and 30 days after it, a series of examinations of the corneal state was made. At the same time points, corneal hydration was assessed by measuring RC. RESULTS: The obtained data confirmed the negative impact of UVB irradiation course on the intensity of tear production and on the corneal thickness and optical parameters. A significant (1.8 times) increase in RC on the 5th day after the irradiation course, followed by a slight decrease on the 30th day after it was revealed. The RC increase measured 5 days after the UVB irradiation course generally corresponded to the increase (by a factor of 1.3) of tear production. RC increase occurred with the corneal edema, which was manifested by corneal thickening (by 18.2% in the middle area and 17.6% in corneal periphery) and an increased volume of corneal tissue (by 17.6%). CONCLUSIONS: Our results demonstrate that the proposed approach can be used for in vivo contactless estimation of the reflectivity of rabbit cornea in the THz range and, thereby, of cornea hydration.
Address National Research University Higher School of Economics, Moscow Institute of Electronics and Mathema, Russia
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1083-3668 ISBN Medium
Area Expedition Conference
Notes PMID:33834684; PMCID:PMC8027227 Approved no
Call Number Serial 1258
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Author Seliverstov, S. V.; Rusova, A. A.; Kaurova, N. S.; Voronov, B. M.; Goltsman, G. N.
Title Attojoule energy resolution of direct detector based on hot electron bolometer Type Conference Article
Year 2016 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume 741 Issue Pages 012165 (1 to 5)
Keywords (up) NbN HEB detector
Abstract We characterize superconducting antenna-coupled NbN hot-electron bolometer (HEB) for direct detection of THz radiation operating at a temperature of 9.0 K. At signal frequency of 2.5 THz, the measured value of the optical noise equivalent power is 2.0×10-13 W-Hz-0.5. The estimated value of the energy resolution is about 1.5 aJ. This value was confirmed in the experiment with pulsed 1.55-μm laser employed as a radiation source. The directly measured detector energy resolution is 2 aJ. The obtained risetime of pulses from the detector is 130 ps. This value was determined by the properties of the RF line. These characteristics make our detector a device-of-choice for a number of practical applications associated with detection of short THz pulses.
Address
Corporate Author Thesis
Publisher IOP Publishing Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Seliverstov_2016 Serial 1337
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Author Seliverstov, S. V.; Anfertyev, V. A.; Tretyakov, I. V.; Ozheredov, I. A.; Solyankin, P. M.; Revin, L. S.; Vaks, V. L.; Rusova, A. A.; Goltsman, G. N.; Shkurinov, A. P.
Title Terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser Type Journal Article
Year 2017 Publication Radiophys. Quant. Electron. Abbreviated Journal Radiophys. Quant. Electron.
Volume 60 Issue 7 Pages 518-524
Keywords (up) NbN HEB mixer, QCL
Abstract We study characteristics of the laboratory prototype of a terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. The results obtained demonstrate the possibility to use this receiver as a basis for creation of a high-sensitivity terahertz spectrometer, which can be used in many basic and practical applications. A significant advantage of this receiver will be the possibility of placing the mixer and heterodyne in the same cryostat, which will reduce the device dimensions considerably. The obtained experimental results are analyzed, and methods of optimizing the parameters of the receiver are proposed.
Address
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 0033-8443 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1322
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Author Tuchak, A. N.; Gol’tsman, G. N.; Kitaeva, G. K.; Penin, A. N.; Seliverstov, S. V.; Finkel, M. I.; Shepelev, A. V.; Yakunin, P. V.
Title Generation of nanosecond terahertz pulses by the optical rectification method Type Journal Article
Year 2012 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 96 Issue 2 Pages 94-97
Keywords (up) optical rectification, lithium niobate crystal
Abstract The possibility of the generation of quasi-cw terahertz radiation by the optical rectification method for broad-band Fourier unlimited nanosecond laser pulses has been experimentally demonstrated. The broadband radiation of a LiF dye-center laser is used as a pump source of a nonlinear optical oscillator. The energy efficiency of terahertz optical frequency conversion in a periodically polarized lithium niobate crystal is 4 × 10−9 at a pump power density of 7 MW/cm2.
Address
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 0021-3640 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1377
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Author Gayduchenko, I. A.; Fedorov, G. E.; Moskotin, M. V.; Yagodkin, D. I.; Seliverstov, S. V.; Goltsman, G. N.; Yu Kuntsevich, A.; Rybin, M. G.; Obraztsova, E. D.; Leiman, V. G.; Shur, M. S.; Otsuji, T.; Ryzhii, V. I.
Title Manifestation of plasmonic response in the detection of sub-terahertz radiation by graphene-based devices Type Journal Article
Year 2018 Publication Nanotechnol. Abbreviated Journal Nanotechnol.
Volume 29 Issue 24 Pages 245204 (1 to 8)
Keywords (up) single layer graphene, graphene nanoribbons
Abstract We report on the sub-terahertz (THz) (129-450 GHz) photoresponse of devices based on single layer graphene and graphene nanoribbons with asymmetric source and drain (vanadium and gold) contacts. Vanadium forms a barrier at the graphene interface, while gold forms an Ohmic contact. We find that at low temperatures (77 K) the detector responsivity rises with the increasing frequency of the incident sub-THz radiation. We interpret this result as a manifestation of a plasmonic effect in the devices with the relatively long plasmonic wavelengths. Graphene nanoribbon devices display a similar pattern, albeit with a lower responsivity.
Address Physics Department, Moscow State University of Education, Moscow 119991, Russia. National Research Center 'Kurchatov Institute', 123182, Moscow, Russia
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 0957-4484 ISBN Medium
Area Expedition Conference
Notes PMID:29553479 Approved no
Call Number Serial 1308
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