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Romanov, N. R., Zolotov, P. I., & Smirnov, K. V. (2019). Development of disordered ultra-thin superconducting vanadium nitride films. In Proc. 8th Int. Conf. Photonics and Information Optics (pp. 425–426).
Abstract: We present the results of development and research of superconducting vanadium nitride VN films ~10 nm thick having different level of disorder. It is showed that both silicon substrate temperature T sub in process of magnetron sputtering and total gas pressure P affect superconducting transition temperature of sputtered films and R 300 /R 20 ratio defining their level of disorder. VN films suitable for development of superconducting single-photon detectors on their basis are obtained.
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Moshkova, M. A., Divochiy, A. V., Morozov, P. V., Antipov, A. V., Vakhtomin, Y. B., & Smirnov, K. V. (2019). Characterization of topologies of superconducting photon number resolving detectors. In Proc. 8th Int. Conf. Photonics and Information Optics (pp. 465–466).
Abstract: Comparative analysis for different topologies of superconducting single-photon detectors with ability to resolve up to 4 photons in a short pulse of IR radiation has been carry out. It was developed the detector with a system detection efficiency of ~ 85 % at λ = 1550 nm. The possibility of using such detector to restore photon statistics of a pulsed radiation source was demonstrated.
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Zolotov, P. I., Vakhtomin, Y. B., Divochiy, A. V., Seleznev, V. A., & Smirnov, K. V. (2016). Technology development of resonator-based structures for efficiency increasing of NBN detectors of IR single photons. Proc. 5th Int. Conf. Photonics and Information Optics, , 115–116.
Abstract: This paper presents a technology of fabrication of NbN superconductive single- photon detectors, using resonator structures. The main results are related to optimization of the process of NbN sputtering over substrate with metallic mirrors and SiO 2 /Si 3 N 4 layers /4 thick. Investigation of the quantum efficiency of fabricated devices at 1.6 K on 1.55 μm showed triple-magnified value compared to standard Si/NbN structures.
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Meledin, D., Tong, C. - Y. E., Blundell, R., & Goltsman, G. (2003). Measurement of intermediate frequency bandwidth of hot electron bolometer mixers at terahertz frequency range. IEEE Microw. Wireless Compon. Lett., 13(11), 493–495.
Abstract: We have developed a new experimental setup for measuring the IF bandwidth of superconducting hot electron bolometer mixers. In our measurement system we use a chopped hot filament as a broadband signal source, and can perform a high-speed IF scan with no loss of accuracy when compared to coherent methods. Using this technique we have measured the 3 dB IF bandwidth of hot electron bolometer mixers, designed for THz frequency operation, and made from 3-4 nm thick NbN film deposited on an MgO buffer layer over crystalline quartz.
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Meledin, D. V., Marrone, D. P., Tong, C. - Y. E., Gibson, H., Blundell, R., Paine, S. N., et al. (2004). A 1-THz superconducting hot-electron-bolometer receiver for astronomical observations. IEEE Trans. Microwave Theory Techn., 52(10), 2338–2343.
Abstract: In this paper, we describe a superconducting hot-electron-bolometer mixer receiver developed to operate in atmospheric windows between 800-1300 GHz. The receiver uses a waveguide mixer element made of 3-4-nm-thick NbN film deposited over crystalline quartz. This mixer yields double-sideband receiver noise temperatures of 1000 K at around 1.0 THz, and 1600 K at 1.26 THz, at an IF of 3.0 GHz. The receiver was successfully tested in the laboratory using a gas cell as a spectral line test source. It is now in use on the Smithsonian Astrophysical Observatory terahertz test telescope in northern Chile.
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