PT Unknown
AU Tarkhov, M
   Morozov, D
   Mauskopf, P
   Seleznev, V
   Korneev, A
   Kaurova, N
   Rubtsova, I
   Minaeva, O
   Voronov, B
   Goltsman, G
TI Single photon counting detector for THz radioastronomy
SE Proc. 17[super:th] Int. Symp. Space Terahertz Technol.
PY 2006
BP 119
EP 122
DE NbN SSPD; SNSPD
AB In this paper we present the results of the research on the superconducting NbN-ultrathin-film single- photon detectors (SSPD) which are capable to detect single quanta in middle IR range. The detection mechanism is based on the hotspot formation in quasi-two-dimensional superconducting structures upon photon absorption. Spectral measurements showed that up to 5.7 gm wavelength (52 THz) the SSPD exhibits single-photon sensitivity. Reduction of operation temperature to 1.6 K allowed us to measure quantum efficiency of -4% at 60 THz. Although further decrease of the operation temperature far below 1 K does not lead to any significant increase of quantum efficiency. We expect that the improvement of the SSPD's performance at reduced operation temperature will make SSPD a practical detector with high characteristics for much lower THz frequencies as well.
ER