|
|
Gol’tsman, G., Korneev, A., Tarkhov, M., Seleznev, V., Divochiy, A., Minaeva, O., et al. (2007). Middle-infrared ultrafast superconducting single photon detector. In 32nd IRMW / 15th ICTE (pp. 115–116).
Abstract: We present the results of the research on quantum efficiency of the ultrathin-film superconducting single-photon detectors (SSPD) in the wavelength rage from 1 mum to 5.7 mum. Reduction of operation temperature to 1.6 K allowed us to measure quantum efficiency of ~1 % at 5.7 mum wavelength with the SSPD made from 4-nm-thick NbN film. In a pursuit of further performance improvement we endeavored SSPD fabricating from 4-nm-thick MoRe film as an alternative material. The MoRe film exhibited transition temperature of 7.7K, critical current density at 4.2 K temperature was 1.1times10 6 A/cm 2 , and diffusivity 1.73 cmVs. The single-photon response was observed with MoRe SSPD at 1.3 mum wavelength with quantum efficiency estimated to be 0.04%.
|
|
|
|
Zolotov, P., Divochiy, A., Korneeva, Y., Vakhtomin, Y., Seleznev, V., & Smirnov, K. (2015). Capability investigation of superconducting single-photon detectors, optimized for 800–1200 nm spectrum range.
|
|
|
|
Zolotov, P., Vakhtomin, Y., Divochiy, A., Seleznev, V., Morozov, P., & Smirnov, K. (2013). High-efficiency single-photon detectors based on NbN films.
Abstract: We present our resent results in development and testing of Superconducting Single-Photon Detectors (SSPD) with detection efficiencies greater than 85%. High values of obtained results are assigned to proposed design of the detector with integrated resonator structure, including two-layer optical cavity and anti-reflective coating (ARC).
|
|
|
|
Zolotov, P., Vakhtomin, Y., Divochiy, A., Morozov, P., Seleznev, V., & Smirnov, K. (2017). Development of fast and high-effective single-photon detector for spectrum range up to 2.3 μm. In Proc. SPBOPEN (pp. 439–440).
Abstract: We present the results of development and testing of the single-photon-counting system operating in the wide spectrum rane up to 2.3 mcm. We managed to increase system detection efficiency up to 60% in the range of 1.7-2.3 mcm optimisation of the fabrication methods of superconducting single-photon detectors and application of the single-mode fiber with enlarged core diameter.
|
|
|
|
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.
|
|
