Kawamura, J., Blundell, R., Tong, C. - Y. E., Papa, D. C., Hunter, T. R., Paine, S. N., et al. (2000). Superconductive hot-electron-bolometer mixer receiver for 800-GHz operation. IEEE Trans. Microw. Theory Techn., 48(4), 683–689.
Abstract: In this paper, we describe a superconductive hot-electron-bolometer mixer receiver designed to operate in the partially transmissive 350-μm atmospheric window. The receiver employs an NbN thin-film microbridge as the mixer element, in which the main cooling mechanism of the hot electrons is through electron-phonon interaction. At a local-oscillator frequency of 808 GHz, the measured double-sideband receiver noise temperature is TRX=970 K, across a 1-GHz intermediate-frequency bandwidth centered at 1.8 GHz. We have measured the linearity of the receiver and the amount of local-oscillator power incident on the mixer for optimal operation, which is PLO≈1 μW. This receiver was used in making observations as a facility instrument at the Heinrich Hertz Telescope, Mt. Graham, AZ, during the 1998-1999 winter observing season.
|
Pentin, I., Finkel, M., Maslennikov, S., Vakhtomin, Y., Smirnov, K., Kaurova, N., et al. (2017). Superconducting hot-electron-bolometer mixers for the mid-IR. Rus. J. Radio Electron., (10), http://jre.cplire.ru/jre/oct17/9/text.pdf.
Abstract: The work presents the result of development of the NbN superconducting hot-electron-bolometer (HEB) mixer. The sensitive element of the mixer is directly coupled to mid-IR radiation, and doesn’t have planar metallic antenna. Investigations of noise characteristics of NbN HEB mixer were performed at the frequency 28.4 THz (λ = 10.6 µm) by using gas-discharge CW CO2-laser without consideration of optical and electrical losses in the heterodyne receiver. The noise temperature of NbN HEB mixer with the size of the sensitive element 10 µm × 10 µm was 2320 K (~ 1.5hν/kB) at the heterodyne frequency of 28.4 THz. The noise temperature was determined by measuring the Y-factor taking into account the term which describes fluctuations of zero-point oscillations in accordance with the fluctuation-dissipation theorem of Calle-Welton. Isothermal method was used to estimate the absorbed heterodyne radiation power which was 9 µW at the optimal operating point for the minimum noise temperature of NbN HEB mixer.
|
Gousev, Y. P., Gol'tsman, G. N., Karasik, B. S., Gershenzon, E. M., Semenov, A. D., Barowski, H. S., et al. (1996). Quasioptical superconducting hot electron bolometer for submillmeter waves. Int. J. of Infrared and Millimeter Waves, 17(2), 317–331.
Abstract: We report on a superconducting hot electron bolometer coupled to radiation via a broadband antenna. The bolometer, a structured NbN film, was patterned on a thin dielectric membrane between terminals of a gold slotline antenna. We investigated the response to submillimeter radiation (wave-lengths ∼ 0.1 mm to 0.7 mm) in the fundamental Gaussian mode. We found that the directivity of the antenna was constant within a factor of 2.5 through the whole experimental range. The noise equivalent power of the bolometer at 119 µm was ∼ 3 · 10−13 W/Hz1/2; a time constant of ∼ 160 ps was estimated.
|
Seliverstov, S. V., Anfertyev, V. A., Tretyakov, I. V., Ozheredov, I. A., Solyankin, P. M., Revin, L. S., et al. (2017). Terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. Radiophys. Quant. Electron., 60(7), 518–524.
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.
|
Tretyakov, I. V., Anfertyev, V. A., Revin, L. S., Kaurova, N. S., Voronov, B. M., Vaks, V. L., et al. (2018). Sensitivity and resolution of a heterodyne receiver based on the NbN HEB mixer with a quantum-cascade laser as a local oscillator. Radiophys. Quant. Electron., 60(12), 988–992.
Abstract: We present the results of experimental studies of the basic characteristics and operation features of a terahertz heterodyne detector based on the superconducting NbN HEB mixer and a quantum cascade laser as a local oscillator operating at a frequency of 2.02 THz. The measured noise temperature of such a mixer amounted to 1500 K. The spectral resolution of the detector is determined by the width of the local-oscillator spectral line whose measured value does not exceed 1 MHz. The quantum-cascade laser could be linearly tuned with respect to frequency with the coefficient 7.2 MHz/mA within the limits of the current oscillation bandwidth.
|
