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Каурова НС, Финкель МИ, Масленников СН, Вахтомин ЮБ, Антипов СВ, Смирнов КВ, et al. Смеситель субмиллиметрового диапазона длин волн на основе тонкой пленки YBa2Cu3O7-x. In: 1-я международная конференция Фундаментальные проблемы высокотемпературной сверхпроводимости. Москва-Звенигород; 2004. 291.
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Slysz W, Wegrzecki M, Bar J, Grabiec P, Gol'tsman GN, Verevkin M, et al. NbN superconducting single-photon detectors coupled with a communication fiber. Vol 37.; 2004.
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Kaurova NS, Finkel MI, Maslennikov SN, Vahtomin YB, Antipov SV, Smirnov KV, et al. Submillimeter mixer based on YBa2Cu3O7-x thin film. In: Proc. 1-st conf. Fundamental problems of high temperature superconductivity. Moscow-Zvenigorod; 2004. 291.
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Antipov SV, Vachtomin YB, Maslennikov SN, Smirnov KV, Kaurova NS, Grishina EV, et al. Noise performance of quasioptical ultrathin NbN hot electron bolometer mixer at 2.5 and 3.8 THz. In: Proc. 5-th MSMW. Vol 2. Kharkov, Ukraine; 2004. p. 592–4.
Abstract: To put space-based and airborne heterodyne instruments into operation at frequencies above 1 THz the superconducting NbN hot-electron bolometer (HEB) will be incorporated into heterodyne receiver as a mixer. At frequencies above 1.3 THz the sensitivity of the NbN HEB mixers outperform the one of the Schottky diodes and SIS-mixers, and the receiver noise temperature of the NbN HEB mixers increase with frequency. In this paper we present the results of the noise temperature measurements within one batch of NbN HEB mixers based on 3.5 mn thick superconducting NbN film grown on Si substrate with MgO buffer layer at the LO frequencies 2.5 THz and 3.8 THz.
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Maslennikov SN, Morozov DV, Ozhegov RV, Smirnov KV, Okunev OV, Gol’tsman GN. Imaging system for submillimeter wave range based on AlGaAs/GaAs hot electron bolometer mixers. In: Proc. 5-th MSMW. Vol 2.; 2004. p. 558–60.
Abstract: Electromagnetic radiation of the submillimeter (SMM) range is dispersed and absorbed significantly less than infrared (IR) radiation when passing through different objects. That is the reason for the development of an SMM imaging system. In this paper, we discuss the design of an SMM heterodyne imager, based on a matrix of AlGaAs/GaAs heterostructure hot electron bolometer mixers (HEB) with relatively high (about 77 K) operating temperature. The predicted double side band (DSB) noise temperature is about 1000 K and optimal local oscillator (LO) power is about 1 /spl mu/W for such mixers, which seems to be quite prospective for an SMM heterodyne imager.
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Vachtomin YB, Antipov SV, Kaurova NS, Maslennikov SN, Smirnov KV, Polyakov SL, et al. Noise temperature, gain bandwidth and local oscillator power of NbN phonon-cooled HEB mixer at terahertz frequenciess. In: Proc. 29th IRMMW / 12th THz. Karlsruhe, Germany; 2004. p. 329–30.
Abstract: We present the performances of HEB mixers based on 3.5 nm thick NbN film integrated with log-periodic spiral antenna. The double side-band receiver noise temperature values are 1300 K and 3100 K at 2.5 THz and at 3.8 THz, respectively. The gain bandwidth of the mixer is 4.2 GHz and the noise bandwidth is 5 GHz. The local oscillator power is 1-3 /spl mu/W for mixers with different active area.
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Il'in K, Siegel M, Semenov A, Engel A, Hübers H-W, Hollmann E, et al. Thickness dependence of superconducting properties of ultrathin Nb and NbN films. In: AKF-Frühjahrstagung.; 2004.
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Hajenius M, Baselmans JJA, Gao JR, Klapwijk TM, de Korte PAJ, Voronov B, et al. Low noise NbN superconducting hot electron bolometer mixers at 1.9 and 2.5 THz. Supercond Sci Technol. 2004;17(5):S224–S228.
Abstract: NbN phonon-cooled hot electron bolometer mixers (HEBs) have been realized with negligible contact resistance between the bolometer itself and the contact structure. Using a combination of in situ cleaning of the NbN film and the use of an additional superconducting interlayer of a 10 nm NbTiN layer between the Au of the contact structure and the NbN film superior noise temperatures have been obtained as low as 950 K at 2.5 THz and 750 K at 1.9 THz. Here we address in detail the DC characterization of these devices, the interface transparencies between the bolometers and the contacts and the consequences of these factors on the mixer performance.
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Klaassen TO, Hovenier JN, Adam AJL, Fischer J, Jakob G, Poglitsch A, et al. Terahertz calorimetry for the Herschel Space Observatory. In: Proc. 29th IRMMW / 12th THz.; 2004. p. 815–6.
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Semenov A, Richter H, Smirnov K, Voronov B, Gol'tsman G, Hübers H-W. The development of terahertz superconducting hot-electron bolometric mixers. Supercond Sci Technol. 2004;17(5):436–9.
Abstract: We present recent advances in the development of NbN hot-electron bolometric (HEB) mixers for flying terahertz heterodyne receivers. Three important issues have been addressed: the quality of the source NbN films, the effect of the bolometer size on the spectral properties of different planar feed antennas, and the local oscillator (LO) power required for optimal operation of the mixer. Studies of the NbN films with an atomic force microscope indicated a surface structure that may affect the performance of the smallest mixers. Measured spectral gain and noise temperature suggest that at frequencies above 2.5 THz the spiral feed provides better overall performance than the double-slot feed. Direct measurements of the optimal LO power support earlier estimates made in the framework of the uniform mixer model.
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