Amorphous superconducting nanowire single-photon detectors integrated with nanophotonic waveguides
Matthias Häußler, M. Yu. Mikhaı̆lov, Martin A. Wolff, Carsten Schuck
Abstract
Future applications in integrated quantum photonics will require large numbers of efficient, fast, and low-noise single-photon counters. Superconducting nanowire single-photon detectors made from amorphous material systems are best suited to meet these demands, but the integration with nanophotonic circuits has remained a challenge. Here, we show how amorphous molybdenum silicide (MoSi) nanowires are integrated with nanophotonic silicon nitride waveguides in traveling wave geometry. We found a saturated on-chip detection efficiency of (73 ± 10) % for telecom wavelength photons and the sub-10 Hz dark count rate at a temperature of 2.1 K, which allows for operation in robust, compact, and economic cryogenic systems. Applications requiring fast counting will benefit from the sub-5 ns recovery times of our devices that we combine with 135 ps timing accuracy. Achieving this performance with waveguide-integrated amorphous superconductors is an important step toward enabling high yield fabrication of competitive single-photon detectors on a large variety of nanophotonic material systems.