Iomdina EN, Seliverstov SV, Sianosyan AA, Teplyakova KO, Rusova AA, Goltsman GN. Terahertz scanning for evaluation of corneal and scleral hydration. STM. 2018;10(4):143–9.
Abstract: The aim of the investigation was to study the prospects of using continuous THz scanning of the cornea and the sclera to determine water concentration in these tissues and on the basis of the obtained data to develop the experimental installation for monitoring corneal and scleral hydration degree.Materials and Methods. To evaluate corneal and scleral transmittance and reflectance spectra in the THz range, the developed experimental installations were used to study 3 rabbit corneas and 3 scleras, 2 whole rabbit eyes, and 3 human scleras. Besides, two rabbit eyes were studied in vivo prior to keratorefractive surgery as well as 10 and 21 days following the surgery (LASIK).Results. There have been created novel experimental installations enabling in vitro evaluation of frequency dependence of corneal and scleral transmittance coefficients and reflectance coefficients on water percentage in the THz range. Decrease in corneal water content by 1% was found to lead to reliably established decrease in the reflected signal by 13%. The reflectance spectrum of the whole rabbit eye was measured in the range of 0.13–0.32 THz. The study revealed the differences between the indices of rabbit cornea and sclera, as well as rabbit and human sclera. There was developed a laboratory model of the installation for in vivo evaluation of corneal and scleral hydration using THz radiation.Conclusion. The preliminary findings show that the proposed technique based on the use of continuous THz radiation can be employed to create a device for noninvasive control of corneal and scleral hydration.
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Gayduchenko IA, Moskotin MV, Matyushkin YE, Rybin MG, Obraztsova ED, Ryzhii VI, et al. The detection of sub-terahertz radiation using graphene-layer and graphene-nanoribbon FETs with asymmetric contacts. In: Materials Today: Proc. Vol 5.; 2018. p. 27301–6.
Abstract: We report on the detection of sub-terahertz radiation using single layer graphene and graphene-nanoribbon FETs with asymmetric contacts (one is the Schottky contact and one – the Ohmic contact). We found that cutting graphene into ribbons a hundred nanometers wide leads to a decrease of the response to sub-THz radiation. We show that suppression of the response in the graphene nanoribbons devices can be explained by unusual properties of the Schottky barrier on graphene-vanadium interface.
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Belosevich VV, Gayduchenko IA, Titova NA, Zhukova ES, Goltsman GN, Fedorov GE, et al. Response of carbon nanotube film transistor to the THz radiation. In: EPJ Web Conf. Vol 195.; 2018. 05012 (1 to 2).
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Tretyakov I, Kaurova N, Raybchun S, Goltsman GN, Silaev AA. Technology for NbN HEB based multipixel matrix of THz range. In: EPJ Web Conf. Vol 195.; 2018. 05011.
Abstract: The influence of homogeneity disorder degree of the thin superconducting NbN film across of Si wafer on characteristics of the Hot Electron Bolometers (HEB) has been investigated. Our experiments have been carried out near the superconducting transition and far below it. The high homogeneity disorder degree of the NbN film has been achieved by preparing the Si substrate surface. The fabricated HEBs all have almost identical R (T) characteristics with a dispersion of Tc and the normal resistance R300 of not more than 0.15K and 2 Ω, respectively. The quality of the devises allows us to demonstrate clearly the influence of non-equilibrium processes in the S’SS’ system on the device performance. Our fabrication technology also allows creating multiplex heterodyne and direct detector matrices based the HEB devices.
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Seliverstov SV, Anfertyev VA, Tretyakov IV, Ozheredov IA, Solyankin PM, Revin LS, et al. Terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. Radiophys Quant Electron. 2017;60(7):518–24.
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.
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