|
|
Shcheslavskiy, V., Morozov, P., Divochiy, A., Vakhtomin, Y., Smirnov, K., & Becker, W. (2016). Erratum: “Ultrafast time measurements by time-correlated single photon counting coupled with superconducting single photon detector” [Rev. Sci. Instrum. 87, 053117 (2016)] (Vol. 87).
Abstract: In the original paper1the Ref. 10 should be M. Sanzaro, N. Calandri, A. Ruggeri, C. Scarcella, G. Boso, M. Buttafava, and A. Tosi, Proc. SPIE9370, 93701T (2015).
|
|
|
|
Smirnov, A. V., Karmantsov, M. S., Smirnov, K. V., Vakhtomin, Y. B., Masterov, D. V., Tarkhov, M. A., et al. (2012). Terahertz response of thin-film YBCO bolometers. Tech. Phys., 57(12), 1716–1719.
Abstract: The bolometric response of high-temperature thin-film YBCO superconducting detectors to an electromagnetic radiation with a frequency of 2.5 THz is measured for the first time. The minimum value of the noise-equivalent power of the detectors is 3.5 × 10−9 W/Hz−−−√. The feasibility of further increasing the sensitivity of the detectors is discussed.
|
|
|
|
Lobanov, Y. V., Vakhtomin, Y. B., Pentin, I. V., Rosental, V. A., Smirnov, K. V., Goltsman, G. N., et al. (2021). Time-resolved measurements of light–current characteristic and mode competition in pulsed THz quantum cascade laser. Optical Engineering, 60(8), 1–8.
Abstract: Quantum cascade lasers (QCL) are widely adopted as prominent and easy-to-use solid-state sources of terahertz radiation. Yet some applications require generation and detection of very sharp and narrow terahertz-range pulses with a specific spectral composition. We have studied time-resolved light-current (L–I) characteristics of multimode THz QCL operated with a fast ramp of the injection current. Detection of THz pulses was carried out using an NbN superconducting hot-electron bolometer with the time constant of the order of 1 ns while the laser bias current was swept during a single driving pulse. A nonmonotonic behavior of the L–I characteristic with several visually separated subpeaks was found. This behavior is associated with the mode competition in THz QCL cavity, which we confirm by L–I measurements with use of an external Fabry–Perot interferometer for a discrete mode selection. We also have demonstrated the possibility to control the L–I shape with suppression of one of the subpeaks by simply adjusting the off-axis parabolic mirror for optimal optical alignment for one of the laser modes. The developed technique paves the way for rapid characterization of pulsed THz QCLs for further studies of the possibilities of using this approach in remote sensing.
|
|
|
|
Zolotov, P., Divochiy, A., Vakhtomin, Y., Moshkova, M., Morozov, P., Seleznev, V., et al. (2018). Photon-number-resolving SSPDs with system detection efficiency over 50% at telecom range. In Proc. AIP Conf. (Vol. 1936, 020019).
Abstract: We used technology of making high-efficiency superconducting single-photon detectors as a basis for improvement of photon-number-resolving devices. By adding optical cavity and using an improved NbN superconducting film, we enhanced previously reported system detection efficiency at telecom range for such detectors. Our results show that implementation of optical cavity helps to develop four-section device with quantum efficiency over 50% at 1.55 µm. Performed experimental studies of detecting multi-photon optical pulses showed irregularities over defining multi-photon through single-photon quantum efficiency.
|
|
|
|
Korneev, A. A., Korneeva, Y. P., Mikhailov, M. Y., Pershin, Y. P., Semenov, A. V., Vodolazov, D. Y., et al. (2015). Characterization of MoSi superconducting single-photon detectors in the magnetic field. IEEE Trans. Appl. Supercond., 25(3), 2200504 (1 to 4).
Abstract: We investigate the response mechanism of nanowire superconducting single-photon detectors (SSPDs) made of amorphous MoxSi1-x. We study the dependence of photon count and dark count rates on bias current in magnetic fields up to 113 mT at 1.7 K temperature. The observed behavior of photon counts is similar to the one recently observed in NbN SSPDs. Our results show that the detecting mechanism of relatively high-energy photons does not involve the vortex penetration from the edges of the film, and on the contrary, the detecting mechanism of low-energy photons probably involves the vortex penetration from the film edges.
|
|
