|
|
Meledin D, Tong CY-E, Blundell R, Kaurova N, Smirnov K, Voronov B, et al. Study of the IF bandwidth of NbN HEB mixers based on crystalline quartz substrate with an MgO buffer layer. IEEE Trans Appl Supercond. 2003;13(2):164–7.
Abstract: In this paper, we present the results of IF bandwidth measurements on 3-4 nm thick NbN hot electron bolometer waveguide mixers, which have been fabricated on a 200-nm thick MgO buffer layer deposited on a crystalline quartz substrate. The 3-dB IF bandwidth, measured at an LO frequency of 0.81 THz, is 3.7 GHz at the optimal bias point for low noise receiver operation. We have also made measurements of the IF dynamic impedance, which allow us to evaluate the intrinsic electron temperature relaxation time and self-heating parameters at different bias conditions.
|
|
|
|
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.
|
|
|
|
Korneeva YP, Mikhailov MY, Pershin YP, Manova NN, Divochiy AV, Vakhtomin YB, et al. Superconducting single-photon detector made of MoSi film. Supercond Sci Technol. 2014;27(9):095012.
Abstract: We fabricated and characterized nanowire superconducting single-photon detectors made of 4 nm thick amorphous Mox Si1−x films. At 1.7 K the best devices exhibit a detection efficiency (DE) up to 18% at 1.2 $\mu {\rm m}$ wavelength of unpolarized light, a characteristic response time of about 6 ns and timing jitter of 120 ps. The DE was studied in wavelength range from 650 nm to 2500 nm. At wavelengths below 1200 nm these detectors reach their maximum DE limited by photon absorption in the thin MoSi film.
|
|
|
|
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.
|
|
|
|
Korneev A, Minaeva O, Rubtsova I, Milostnaya I, Chulkova G, Voronov B, et al. Superconducting single-photon ultrathin NbN film detector. Quantum Electronics. 2005;35(8):698–700.
Abstract: Superconducting single-photon ultrathin NbN film detectors are studied. The development of manufacturing technology of detectors and the reduction of their operating temperature down to 2 K resulted in a considerable increase in their quantum efficiency, which reached in the visible region (at 0.56 μm) 30%—40%, i.e., achieved the limit determined by the absorption coefficient of the film. The quantum efficiency exponentially decreases with increasing wavelength, being equal to ~20% at 1.55 μm and ~0.02% at 5 μm. For the dark count rate of ~10-4s-1, the experimental equivalent noise power was 1.5×10-20 W Hz-1/2; it can be decreased in the future down to the record low value of 5×10-21 W Hz-1/2. The time resolution of the detector is 30 ps.
|
|
|
|
Verevkin A, Zhang J, Sobolewski R, Lipatov A, Okunev O, Chulkova G, et al. Detection efficiency of large-active-area NbN single-photon superconducting detectors in the ultraviolet to near-infrared range. Appl. Phys. Lett.. 2002;80(25):4687–9.
Abstract: We report our studies on spectral sensitivity of meander-type, superconducting NbN thin-film single-photon detectors (SPDs), characterized by GHz counting rates of visible and near-infrared photons and negligible dark counts. Our SPDs exhibit experimentally determined quantum efficiencies ranging from ∼0.2% at the 1.55 μm wavelength to ∼70% at 0.4 μm. Spectral dependences of the detection efficiency (DE) at the 0.4 to 3.0-μm-wavelength range are presented. The exponential character of the DE dependence on wavelength, as well as its dependence versus bias current, is qualitatively explained in terms of superconducting fluctuations in our ultrathin, submicron-width superconducting stripes. The DE values of large-active-area NbN SPDs in the visible range are high enough for modern quantum communications.
|
|
|
|
Maslennikov S, Antipov S, Shishkov A, Svechnikov S, Voronov B, Smirnov K, et al. NbN HEB mixer noise temperature measurements with hot/cold load mounted inside the helium cryostat at 300 GHz. In: Proc. Int. Student Seminar on Microwave Appl. of Novel Physical Phenomena supported by IEEE. St.-Petersburg: LETI; 2002.
|
|
|
|
Ozhegov R, Morozov D, Maslennikov S, Okunev O, Smirnov K, Gol'tsman G. Submillimeter wave range imaging system for registering human body radiation and finding out the things covered under clothes. In: Proc. 3rd Int. exhibition and conf. Non-Destructive Testing Equipment and Devices. Moscow; 2004.
|
|
|
|
Ozhegov R, Maslennikov S, Morozov D, Okunev O, Smirnov K, Gol'tsman G. Imaging system for submillimeter wave range. In: Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10). Moscow; 2004.
|
|
|
|
Maslennikov S, Vachtomin Y, Antipov S, Smirnov K, Kaurova N, Grishina E, et al. NbN HEB mixers for frequencies of 2.5 and 3.8 THz. In: Proc. Tenth All-Russian sceintific conference of student-physicists and young sceintists (VNKSF-10). Moscow; 2004.
|
|
