Superconducting nanowire single-photon detectors integrated with composite optical systems for quantum information

顾敏, 康琳, 张蜡宝 +6 more

Michael G. Tanner, L. San Emeterio Alvarez, Weitao Jiang +3 more

Superconducting nanowire single photon detectors (SNSPDs) are a key enabling technology for optical quantum information science. In this paper we demonstrate a SNSPD fabricated on lithium niobate, an important material for high speed integrated photonic circuits. We report a system detection efficiency of 0.15% at a 1 kHz dark count rate with a maximum of ~1% close to the critical current at 1550 nm wavelength for a parallel wire SNSPD with front side illumination. There is clear scope for improving on this performance with further materials optimization. Detector integration with a lithium niobate optical waveguide is simulated, demonstrating the potential for high single photon detection efficiency in an integrated quantum optic circuit.

Shigehito Miki, Taro Yamashita, Mikio Fujiwara +2 more

Min Gu, Lin Kang, Labao Zhang +5 more

Superconducting nanowire single-photon detectors (SNSPDs) with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance system detection efficiency and count rates. Numerical simulation by finite-difference time-domain method shows that the photon absorption capacity of SNSPDs with a composite optical structure can be enhanced significantly by adjusting the parameters of the phase-grating and optical cavity structures. The absorption capacity of the superconducting nanowires reached 69.8% at the wavelength of 850 nm with 0.3 filling factor. When the filling factor was reduced to only 0.08, the absorption capacity is still 48.52%. It greatly decreased the kinetic inductance of SNSPDs, and improved the count rates.

Chandra M. Natarajan, Martin M. Härtig, Ryan E. Warburton +8 more

Carsten Schuck

Quantum technologies and optical sensors with ultimate sensitivity require efficient counting of single photons. Superconducting nanowire single-photon detectors have set leading performance benchmarks in this regard but evolving from stand-alone fiber-coupled detectors to highly integrated receivers with large numbers of photonic channels and configurable optical functionalities has remained a challenge. Here we show how large numbers of superconducting nanowire single-photon detectors with high detection efficiency and low timing jitter can be integrated with nanophotonic circuits. The latter allow for combining photon counting capabilities of superconducting nanowires with active and passive optical control functionalities, such as switching, phase shifting and photon number resolution, which we demonstrate for leading photonic integrated circuit platforms. Broadband optical interconnects produced in 3D direct laser writing enable competitive system detection efficiency, which we can reproduce in a receiver unit that integrates 64 individually addressable superconducting nanowire single-photon detectors. We show that the system is well-suited for massively parallelized quantum key distribution, achieving secret key generation rates beyond 10 Mbit/sec in a field test. Integrating large numbers of superconducting nanowire single photon detectors with optical waveguides on configurable nanophotonic chips offers a wide range of applications in quantum communication, information processing and sensing.