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Yamashita T, Miki S, Qiu W, Fujiwara M, Sasaki M, Wang Z. Temperature dependent performances of superconducting nanowire single-photon detectors in an ultralow-temperature region. IEEE Trans. Appl. Supercond.. 2010;21(3):336–9.
Abstract: We report on the performance of a fiber-coupled superconducting nanowire single-photon detector (SNSPD) from 4 K down to the ultralow temperature of 16 mK for a 1550 nm wave length. The system detection efficiency (DE) increased with de creasing the temperature and reached the considerably high value of 15% with a dark count rate less than 100 cps below 1.5 K, even without an optical cavity structure. We also observed saturation of the system DE in its bias current dependency at 16 mK, which indicates that the device DE of our SNSPD nearly reached intrinsic DE despite the device having a large active area of 20 μm × 20 μm. The dark count was finite even at 16 mK and the black body radiation becomes its dominant origin in the low temperatures for fiber-coupled devices.
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Jang YR, Yoo K-H, Park SM. Rapid thermal annealing of ZnO thin films grown at room temperature. J. Vac. Sci. Technol. A. 2010;28(2):4.
Abstract: The authors successfully obtained high quality ZnO thin films by growing them at room temperature (RT) and postannealing by rapid thermal annealing (RTA). The thin films were grown by pulsed laser deposition on Si (100) substrates at RT, and RTA was performed under various temperatures and ambient conditions. Based on the UV emission to visible emission ratio in RT photoluminescence (PL) spectra, the optimum film was obtained at annealing temperature ~700 °C in an ambient of Ar, N2, or O2 at 0.1 Torr, while the optimum annealing temperature was above 1100 °C in the air ambient at atmospheric pressure. The morphology and structure of the films in different RTA conditions were investigated by using field emission scanning electron microscopy and grazing incidence x-ray diffraction, and were discussed in conjunction with the PL data.
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Hoeffgen SK, Kuhnhenn J, Weinand U. High radiation sensitivity of chiral long period gratings. IEEE Trans. Nucl. Sci.. 2010;57(5):2915–22.
Abstract: The radiation sensitivity of chiral long period gratings was investigated for the first time. After a Co-60 gamma dose of 100 kGy they show radiation-induced changes of their transmission dip wavelength of up to 10 nm, which is 100 to 1000 times higher than the radiation-induced wavelength shift of different fiber Bragg grating types. They can therefore be used as radiation sensors down to doses of 10 Gy or even below, but not for accurate dose measurements since the size of the wavelength shift after a certain dose still depends on the radiation dose rate. Chiral gratings made of eight single mode fiber types with differences of their radiation-induced attenuation of several orders of magnitude were investigated in order to look for a correlation between dip wavelength shift and fiber attenuation. However, the dip wavelength curves do not show exactly the same order as the fiber attenuation curves. A theory that can exactly predict all properties of the chiral gratings might enable us to specify from our results an optimized fiber for the production of gratings that can also be used for radiation dosimetry.
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Smirnov KV, Vakhtomin YB, Divochiy AV, Ozhegov RV, Pentin IV, Gol'tsman GN. Infrared and terahertz detectors on basis of superconducting nanostructures. In: IEEE, editor. Microwave and Telecom. Technol. (CriMiCo), 20th Int. Crimean Conf.; 2010. p. 823–4.
Abstract: Results of development of single-photon receiving systems of visible, infrared and terahertz range based on thin-film superconducting nanostructures are presented. The receiving systems are produced on the basis of superconducting nanostructures, which function by means of hot-electron phenomena.
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Goltsman GN, Korneev AA, Finkel MI, Divochiy AV, Florya IN, Korneeva YP, et al. Superconducting hot-electron bolometer as THz mixer, direct detector and IR single-photon counter [abstract]. In: 35th Int. Conf. Infrared, Millimeter, and Terahertz Waves.; 2010. p. 1.
Abstract: We present a new generation of superconducting single-photon detectors (SSPDs) and hot-electron superconducting sensors with record characteristic for many terahertz and optical applications.
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