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Kinch MA, Wan C-F Beck J. D. 1/f noise in HgCdTe photodiodes. J. Electron. Mater.. 2005;34(6):928–32.
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Shelkovnikov A, Grain C, Nguyen CT, Butcher RJ, Amy-Klein A, Chardonnet C. 500-Hz two-photon Ramsey fringes with a SF6 beam: towards a new frequency standard in the 30-THz spectral region. Appl Phys B: Lasers and Optics. 2001;73:93–8.
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Zwiller V<cc><81>ry, Blom H, Jonsson P, Panev N, Jeppesen S, Tsegaye T, et al. Single quantum dots emit single photons at a time: Antibunching experiments. Appl Phys Lett. 2001;78(17):2476.
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Semenov A, Engel A, Il'in K, Gol'tsman G, Siegel M, Hübers H-W. Ultimate performance of a superconducting quantum detector. Eur Phys J Appl Phys. 2003;21(3):171–8.
Abstract: We analyze the ultimate performance of a superconducting quantum detector in order to meet requirements for applications in near-infrared astronomy and X-ray spectroscopy. The detector exploits a combined detection mechanism, in which avalanche quasiparticle multiplication and the supercurrent jointly produce a voltage response to a single absorbed photon via successive formation of a photon-induced and a current-induced normal hotspot in a narrow superconducting strip. The response time of the detector should increase with the photon energy providing energy resolution. Depending on the superconducting material and operation conditions, the cut-off wavelength for the single-photon detection regime varies from infrared waves to visible light. We simulated the performance of the background-limited infrared direct detector and X-ray photon counter utilizing the above mechanism. Low dark count rate and intrinsic low-frequency cut-off allow for realizing a background limited noise equivalent power of 10−20 W Hz−1/2 for a far-infrared direct detector exposed to 4-K background radiation. At low temperatures, the intrinsic response time of the counter is rather determined by diffusion of nonequilibrium electrons than by the rate of energy transfer to phonons. Therefore, thermal fluctuations do not hamper energy resolution of the X-ray photon counter that should be better than 10−3 for 6-keV photons. Comparison of new data obtained with a Nb based detector and previously reported results on NbN quantum detectors support our estimates of ultimate detector performance.
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Semenov AD, Il'in K, Siegel M, Smirnov A, Pavlov S, Richter H, et al. Evidence of non-bolometric mixing in the bandwidth of a hot-electron bolometer. Supercond Sci Technol. 2006;19(10):1051–6.
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Semenov AD, Richter H, Hubers H-W, Gunther B, Smirnov A, Il'in KS, et al. Terahertz performance of integrated lens antennas with a hot-electron bolometer. IEEE Trans. Microw. Theory Techn.. 2007;55(2):239–47.
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Lee J-H, Kim D-W, Wu Y-H, Yu C-J, Lee S-D, Wu S-T. High-speed infrared phase modulators using short helical pitch ferroelectric liquid crystals. Opt Express. 2005;13(20):7732.
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Schwaab GW, Sirmain G, Schubert J, Hubers H-W, Gol'tsman G, Cherednichenko S, et al. Investigation of NbN phonon-cooled HEB mixers at 2.5 THz. IEEE Trans Appl Supercond. 1999;9(2):4233–6.
Abstract: The development of superconducting hot electron bolometric (HEB) mixers has been a big step forward in the direction of quantum noise limited mixer performance at THz frequencies. Such mixers are crucial for the upcoming generation of airborne and spaceborne THz heterodyne receivers. In this paper we report on new results on a phonon-cooled NbN HEB mixer using e-beam lithography. The superconducting film is 3 nm thick. The mixer is 0.2 μm long and 1.5 μm wide and it is integrated in a spiral antenna on a Si substrate. The device is quasi-optically coupled through a Si lens and a dielectric beam combiner to the radiation of an optically pumped FIR ring gas laser cavity. The performance of the mixer at different THz frequencies from 0.69 to 2.55 THz with an emphasis on 2.52 THz is demonstrated. At 2.52 THz minimum DSB noise temperatures of 4200 K have been achieved at an IF of 1.5 GHz and a bandwidth of 40 MHz with the mixer mounted in a cryostat and a 0.8 m long signal path in air.
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Ryabchun S, Tong C-YE, Blundell R, Gol'tsman G. Stabilization scheme for hot-electron bolometer receivers using microwave radiation. IEEE Trans Appl Supercond. 2009;19(1):14–9.
Abstract: We present the results of a stabilization scheme for terahertz receivers based on NbN hot-electron bolometer (HEB) mixers that uses microwave radiation with a frequency much lower than the gap frequency of NbN to compensate for mixer current fluctuations. A feedback control loop, which actively controls the power level of the injected microwave radiation, has successfully been implemented to stabilize the operating point of the HEB mixer. This allows us to increase the receiver Allan time to 10 s and also improve the temperature resolution of the receiver by about 30% in the total power mode of operation.
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Cherednichenko S, Drakinskiy V, Baubert J, Krieg J-M, Voronov B, Gol'tsman G, et al. Gain bandwidth of NbN hot-electron bolometer terahertz mixers on 1.5 μm Si3N4 / SiO2 membranes. J Appl Phys. 2007;101(12):124508 (1 to 6).
Abstract: The gain bandwidth of NbN hot-electron bolometer terahertz mixers on electrically thin Si3N4/SiO2 membranes was experimentally investigated and compared with that of HEB mixers on bulk substrates. A gain bandwidth of 3.5 GHz is achieved on bulk silicon, whereas the gain bandwidth is reduced down to 0.6–0.9 GHz for mixers on 1.5 μm Si3N4/SiO2 membranes. We show that application of a MgO buffer layer on the membrane extends the gain bandwidth to 3 GHz. The experimental data were analyzed using the film-substrate acoustic mismatch approach.
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