PT Journal
AU Słysz, W
   Wegrzecki, M
   Bar, J
   Grabiec, P
   Górska, M
   Zwiller, V
   Latta, C
   Böhi, P
   Pearlman, AJ
   Cross, AS
   Pan, D
   Kitaygorsky, J
   Komissarov, I
   Verevkin, A
   Milostnaya, I
   Korneev, A
   Minayeva, O
   Chulkova, G
   Smirnov, K
   Voronov, B
   Gol’tsman, GN
   Sobolewski, R
TI Fibre-coupled, single photon detector based on NbN superconducting nanostructures for quantum communications
SO J. Modern Opt.
JI J. Modern Opt.
PY 2007
BP 315
EP 326
VL 54
IS 2-3
DI 10.1080/09500340600779496
DE NbN SSPD; SNSPD
AB We present a novel, two-channel, single photon receiver based on two fibre-coupled, NbN, superconducting, single photon detectors (SSPDs). The SSPDs are nanostructured superconducting meanders and are known for ultrafast and efficient detection of visible-to-infrared photons. Coupling between the NbN detector and optical fibre was achieved using a micromechanical photoresist ring placed directly over the SSPD, holding the fibre in place. With this arrangement, we obtained coupling efficiencies up to ∼30%. Our experimental results showed that the best receiver had a near-infrared system quantum efficiency of 0.33% at 4.2 K. The quantum efficiency increased exponentially with the photon energy increase, reaching a few percent level for visible-light photons. The photoresponse pulses of our devices were limited by the meander high kinetic inductance and had the rise and fall times of approximately 250 ps and 5 ns, respectively. The receiver's timing jitter was in the 37 to 58 ps range, approximately 2 to 3 times larger than in our older free-space-coupled SSPDs. We stipulate that this timing jitter is in part due to optical fibre properties. Besides quantum communications, the two-detector arrangement should also find applications in quantum correlation experiments.
ER