PT Unknown
AU Gol’tsman, G
   Korneev, A
   Tarkhov, M
   Seleznev, V
   Divochiy, A
   Minaeva, O
   Kaurova, N
   Voronov, B
   Okunev, O
   Chulkova, G
   Milostnaya, I
   Smirnov, K
TI Middle-infrared ultrafast superconducting single photon detector
SE 32nd IRMW / 15th ICTE
PY 2007
BP 115
EP 116
DI 10.1109/ICIMW.2007.4516419
DE SSPD; SNSPD
AB 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%.
ER