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Elezov, M., Ozhegov, R., Goltsman, G., & Makarov, V. (2019). Countermeasure against bright-light attack on superconducting nanowire single-photon detector in quantum key distribution. Opt. Express, 27(21), 30979–30988.
Abstract: We present an active anti-latching system for superconducting nanowire single-photon detectors. We experimentally test it against a bright-light attack, previously used to compromise security of quantum key distribution. Although our system detects continuous blinding, the detector is shown to be partially blindable and controllable by specially tailored sequences of bright pulses. Improvements to the countermeasure are suggested.
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Iomdina, E. N., Goltsman, G. N., Seliverstov, S. V., Sianosyan, A. A., Teplyakova, K. O., & Rusova, A. A. (2016). Study of transmittance and reflectance spectra of the cornea and the sclera in the THz frequency range. J. Biomed. Opt., 21(9), 97002 (1 to 5).
Abstract: An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells: the cornea and the sclera. Adequate control of corneal and scleral hydration is very important for early diagnosis of a variety of eye diseases, stating indications for and contraindications against keratorefractive surgeries and the choice of contact lens correction solutions. THz systems of creating images in reflected beams are likely to become ideal instruments of noninvasive control of corneal and scleral hydration degrees. This paper reports on the results of a study involving transmittance and reflectance spectra for the cornea and the sclera of rabbit and human eyes, as well as those of the rabbit eye, in the frequency range of 0.13 to 0.32 THz. The dependence of the reflectance coefficient of these tissues on water mass percentage content was determined. The experiments were performed on three corneas, three rabbit scleras, two rabbit eyes, and three human scleras. The preliminary results demonstrate that the proposed technique, based on the use of a continuous THz radiation, may be utilized to create a device for noninvasive control of corneal and scleral hydration, which has clear potential of broad practical application.
Keywords: BWO, IMPATT diode, Schottky diode, medicine, animals, cornea, physiology, humans, rabbits, sclera diagnostic imaging, physiology
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Sclafani, M., Marksteiner, M., Keir, F. M. L., Divochiy, A., Korneev, A., Semenov, A., et al. (2012). Sensitivity of a superconducting nanowire detector for single ions at low energy. Nanotechnol., 23(6), 065501 (1 to 5).
Abstract: We report on the characterization of a superconducting nanowire detector for ions at low kinetic energies. We measure the absolute single-particle detection efficiency eta and trace its increase with energy up to eta = 100%. We discuss the influence of noble gas adsorbates on the cryogenic surface and analyze their relevance for the detection of slow massive particles. We apply a recent model for the hot-spot formation to the incidence of atomic ions at energies between 0.2 and 1 keV. We suggest how the differences observed for photons and atoms or molecules can be related to the surface condition of the detector and we propose that the restoration of proper surface conditions may open a new avenue for SSPD-based optical spectroscopy on molecules and nanoparticles.
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Nasr, M. B., Minaeva, O., Goltsman, G. N., Sergienko, A. V., Saleh, B. E., & Teich, M. C. (2008). Submicron axial resolution in an ultrabroadband two-photon interferometer using superconducting single-photon detectors. Opt. Express, 16(19), 15104–15108.
Abstract: We generate ultrabroadband biphotons via the process of spontaneous parametric down-conversion in a quasi-phase-matched nonlinear grating that has a linearly chirped poling period. Using these biphotons in conjunction with superconducting single-photon detectors (SSPDs), we measure the narrowest Hong-Ou-Mandel dip to date in a two-photon interferometer, having a full width at half maximum (FWHM) of approximately 5.7 fsec. This FWHM corresponds to a quantum optical coherence tomography (QOCT) axial resolution of 0.85 µm. Our results indicate that a high flux of nonoverlapping biphotons may be generated, as required in many applications of nonclassical light.
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Nebosis, R. S., Heusinger, M. A., Semenov, A. D., Lang, P. T., Schatz, W., Steinke, R., et al. (1993). Ultrafast photoresponse of an YBa2Cu3O7-δ film to far-infrared radiation pulses. Opt. Lett., 18(2), 96–97.
Abstract: We report the observation of an ultrafast photoresponse of a high-T(c), film to far-infrared radiation pulses. The response of a sample, consisting of a current-carrying structured YBa(2)Cu(3)O(7-delta) film cooled to liquid-nitrogen temperature, was studied by use of ultrashort laser pulses from an optically pumped far-infrared laser in the frequency range from 0.7 to 7 THz. We found that the response time was limited by the time resolution, 120 ps, of our electronic registration equipment.
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