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Ozhegov, R., Maslennikov, S., Morozov, D., Okunev, O., Smirnov, K., & Gol'tsman, G. (2004). Imaging system for submillimeter wave range. In Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10). Moscow.
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Baubert, J., Salez, M., Merkel, H., Pons, P., Cherednichenko, S., Lecomte, B., et al. (2005). IF gain bandwidth of membrane-based NbN hot electron bolometers for SHAHIRA. IEEE Trans. Appl. Supercond., 15(2), 507–510.
Abstract: SHAHIRA (Submm Heterodyne Array for HIgh-speed Radio Astronomy) is a project supported by the European Space Agency (ESA) and is designed to fly on the SOFIA observatory. A quasi-optic design has been chosen for 2.5/2.7 THz and 4.7 THz, for hydroxyde radical OH, deuterated hydrogen HD and neutral atomic oxygen OI lines observations. Hot electron bolometers (HEBs) have been processed on 1 /spl mu/m thick SiO/sub 2//Si/sub 3/N/sub 4/ stress-less membranes. In this paper we analyse the intermediate frequency (IF) gain bandwidth from the theoretical point of view, and compare it to measurements.
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Cao, A., Jiang, L., Chen, S. H., Antipov, S. V., & Shi, S. C. (2007). IF gain bandwidth of a quasi-optical NbN superconducting HEB mixer. In Proc. International conference on microwave and millimeter wave technology (pp. 1–3). Builin.
Abstract: In this paper, the intermediate frequency (IF) gain bandwidth of a quasi-optical NbN superconducting hot-electron bolometer (HEB) mixer is investigated at 500 GHz with an IF system incorporating with a frequency down-converting scheme which is able to sweep the IF signal in a frequency range of 0.3-4 GHz. The IF gain bandwidth of the device is measured to be 1.5 GHz when it is biased at a voltage of the minimum noise temperature, and becomes larger when the bias voltage increases.
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Cherednichenko, S., Kroug, M., Yagoubov, P., Merkel, H., Kollberg, E., Yngvesson, K. S., et al. (2000). IF bandwidth of phonon cooled HEB mixers made from NbN films on MgO substrates. In Proc. 11th Int. Symp. Space Terahertz Technol. (pp. 219–227).
Abstract: An investigation of gain and noise bandwidth of phonon-cooled hot-electron bolometric (HEB) mixers is presented. The radiation coupling to the mixers is quasioptical through either a spiral or twin-slot antenna. A maximum gain bandwidth of 4.8 GHz is obtained for mixers based on a 3.5 nm thin NbN film with Tc= 10 K. The noise bandwidth is 5.6 GHz, at the moment limited by parasitic elements in the, device mount fixture. At 0.65 THz the DSB receiver noise temperature is 700-800 К in the IF band 1-2 GHz, and 1150-2700 К in the band 3.5-7 GHz.
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Ferrari, S., Kovalyuk, V., Hartmann, W., Vetter, A., Kahl, O., Lee, C., et al. (2017). Hot-spot relaxation time current dependence in niobium nitride waveguide-integrated superconducting nanowire single-photon detectors. Opt. Express, 25(8), 8739–8750.
Abstract: We investigate how the bias current affects the hot-spot relaxation dynamics in niobium nitride. We use for this purpose a near-infrared pump-probe technique on a waveguide-integrated superconducting nanowire single-photon detector driven in the two-photon regime. We observe a strong increase in the picosecond relaxation time for higher bias currents. A minimum relaxation time of (22 +/- 1)ps is obtained when applying a bias current of 50% of the switching current at 1.7 K bath temperature. We also propose a practical approach to accurately estimate the photon detection regimes based on the reconstruction of the measured detector tomography at different bias currents and for different illumination conditions.
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Dzardanov, A., Ekstrom, H., Gershenzon, E., Gol'tsman, G., Jacobsson, S., Karasik, B., et al. (1994). Hot-electron superconducting mixers for 20-500 GHz operation. In Proc. Int. Conf. on Millimeter and Submillimeter Waves and Appl. (Vol. 2250, pp. 276–278).
Abstract: Bolometdcmucers based on Nb and NbN superconducting thin films in the resistive state have been prepared for 20, 100 GHz and 350-500 GHz operation. The mixing mechanism is presumably of electron heating origin. Our measurements indicate that a conversion loss of about 6-8 dB can rather easily be achieved, and that the noise is reasonably low. The requirements on the operation mode and on the film parameters in order to obtain small conversion losses or even gain are discussed. For NbN films the availability of nearly 1 GHz IF bandwidth is experimentally demonstrated. NbN hot-electron mucers combined with slot-line tapered antenna on Si membrane or with double-dipole antenna on SiO^ substrate have been fabricated. The devices we study are considered to be very promising for use in heterodyne receivers from microwaves to terahertz frequencies.
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Gershenzon, E. M., & Gol'tsman, G. N. (1993). Hot-electron superconducting mixers. In J. R. Birch, & T. J. Parker (Eds.), Proc. SPIE (Vol. 2104, pp. 329–330). SPIE.
Abstract: The creation of low noise heterodyne receivers for frequencies above 1 THz is in the urgentneed for radio astronomy, laser spectroscopy, plasma diagnostic, etc. In this paper we discussthe nonlinear effect related to hot electrons in superconductors, and their potential use in lownoise submilimeter wave mixer. We also discuss results achieved so far as well as possible futuredevelopments.
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Semenov, A. D., Gol'tsman, G. N., & Sobolewski, R. (2002). Hot-electron effect in superconductors and its applications for radiation sensors. Supercond. Sci. Technol., 15(4), R1–R16.
Abstract: The paper reviews the main aspects of nonequilibrium hot-electron phenomena in superconductors and various theoretical models developed to describe the hot-electron effect. We discuss implementation of the hot-electron avalanche mechanism in superconducting radiation sensors and present the most successful practical devices, such as terahertz mixers and direct intensity detectors, for far-infrared radiation. Our presentation also includes the novel approach to hot-electron quantum detection implemented in superconducting x-ray to optical photon counters.
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Tretyakov, I. V., Finkel, M. I., Ryabchun, S. A., Kardakova, A. I., Seliverstov, S. V., Petrenko, D. V., et al. (2014). Hot-electron bolometer mixers with in situ contacts. Radiophys. Quant. Electron., 56(8-9), 591–598.
Abstract: We report on the latest achievements in the development of superconducting hot-electron bolometer (HEB) mixers for terahertz superheterodyne receivers. We consider application ranges of such receivers and requirements for the basic characteristics of the mixers. Main features of the mixers, such as noise temperature, gain bandwidth, noise bandwidth, and required local-oscillator power, have been improved significantly over the past few years due to intense research work, both in terms of the element fabrication quality and in terms of understanding of the physics of the processes occurring in the HEB mixers. Contacts between the superconducting bridge and the planar antenna play a key role in the mixer operation. Improvement of the quality of the contacts leads simultaneously to a decrease in the noise temperature and an increase in the gain bandwidth of a mixer.
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Yagoubov, P., Hübers, H. - W., Gol’tsman, G., Semenov, A., Gao, J., Hoogeveen, R., et al. (2001). Hot-electron bolometer mixers – technology for far-infrared heterodyne instruments in future atmospheric chemistry missions. In S. Buehler, & Berlin (Eds.), Proc. 3rd Int. Symp. Submillimeter Wave Earth Observation From Space (pp. 57–69). Logos-Verlag.
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