PT Journal
AU Vetter, A
   Ferrari, S
   Rath, P
   Alaee, R
   Kahl, O
   Kovalyuk, V
   Diewald, S
   Goltsman, GN
   Korneev, A
   Rockstuhl, C
   Pernice, WHP
TI Cavity-enhanced and ultrafast superconducting single-photon detectors
SO Nano Lett.
JI Nano Lett.
PY 2016
BP 7085
EP 7092
VL 16
IS 11
DI 10.1021/acs.nanolett.6b03344
LA English
DE SSPD; SNSPD; multiphoton detection; nanophotonic circuit; photonic crystal cavity
AB Ultrafast single-photon detectors with high efficiency are of utmost importance for many applications in the context of integrated quantum photonic circuits. Detectors based on superconductor nanowires attached to optical waveguides are particularly appealing for this purpose. However, their speed is limited because the required high absorption efficiency necessitates long nanowires deposited on top of the waveguide. This enhances the kinetic inductance and makes the detectors slow. Here, we solve this problem by aligning the nanowire, contrary to usual choice, perpendicular to the waveguide to realize devices with a length below 1 mum. By integrating the nanowire into a photonic crystal cavity, we recover high absorption efficiency, thus enhancing the detection efficiency by more than an order of magnitude. Our cavity enhanced superconducting nanowire detectors are fully embedded in silicon nanophotonic circuits and efficiently detect single photons at telecom wavelengths. The detectors possess subnanosecond decay ( approximately 120 ps) and recovery times ( approximately 510 ps) and thus show potential for GHz count rates at low timing jitter ( approximately 32 ps). The small absorption volume allows efficient threshold multiphoton detection.
ER