PT Unknown
AU Korneev, A
   Minaeva, O
   Divochiy, A
   Antipov, A
   Kaurova, N
   Seleznev, V
   Voronov, B
   Gol’tsman, G
   Pan, D
   Kitaygorsky, J
   Slysz, W
   Sobolewski, R
TI Ultrafast and high quantum efficiency large-area superconducting single-photon detectors
SE Proc. SPIE
PY 2007
BP 65830I (1 to 9)
VL 6583
DI 10.1117/12.723684
DE SSPD; SNSPD; superconducting NbN films; infrared single-photon detectors
AB We present our latest generation of superconducting single-photon detectors (SSPDs) patterned from 4-nm-thick NbN films, as meander-shaped  0.5-mm-long and  100-nm-wide stripes. The SSPDs exhibit excellent performance parameters in the visible-to-near-infrared radiation wavelengths: quantum efficiency (QE) of our best devices approaches a saturation level of  30% even at 4.2 K (limited by the NbN film optical absorption) and dark counts as low as 2x10[super:-4] Hz. The presented SSPDs were designed to maintain the QE of large-active-area devices, but, unless our earlier SSPDs, hampered by a significant kinetic inductance and a nanosecond response time, they are characterized by a low inductance and GHz counting rates. We have designed, simulated, and tested the structures consisting of several, connected in parallel, meander sections, each having a resistor connected in series. Such new, multi-element geometry led to a significant decrease of the device kinetic inductance without the decrease of its active area and QE. The presented improvement in the SSPD performance makes our detectors most attractive for high-speed quantum communications and quantum cryptography applications.
ER