Detecting single infrared photons toward optimal system detection efficiency

Abstract

Superconducting nanowire single-photon detector (SNSPD) with near-unity system efficiency is a key enabling, but still elusive technology for numerous quantum fundamental theory verifications and quantum information applications. The key challenge is to have both a near-unity photon-response probability and absorption efficiency simultaneously for the meandered nanowire with a finite filling ratio, which is more crucial for NbN than other superconducting materials (e.g., WSi) with lower transition temperatures. Here, we overcome the above challenge and produce NbN SNSPDs with a record system efficiency by replacing a single-layer nanowire with twin-layer nanowires on a dielectric mirror. The detector at 0.8 K shows a maximal system detection efficiency (SDE) of 98% at 1590 nm and a system efficiency of over 95% in the wavelength range of 1530-1630 nm. Moreover, the detector at 2.1K demonstrates a maximal SDE of 95% at 1550 nm using a compacted two-stage cryocooler. This type of detector also shows the robustness against various parameters, such as the geometrical size of the nanowire, and the spectral bandwidth, enabling a high yield of 73% (36%) with an SDE of >80% (90%) at 2.1K for 45 detectors fabricated in the same run. These SNSPDs made of twin-layer nanowires are of important practical significance for batch production.

Superconducting microstrip single-photon detector with system detection efficiency over 90% at 1550 nm

“…Superconducting nanowire single-photon detectors (SNSPDs) [1] have been proven as one of the most attractive single-photon detectors, as they provide high system detection efficiency (SDE) [2][3][4], low dark count rate (DCR) [5], low timing jitter (TJ) [6,7], high count rate (CR) [8], and broadband sensitivity [9,10]. To date, SNSPDs have been used in many applications, such as quantum key distribution [11,12], photonic Boson sampling [13], dark matter detection [14,15], and satellite laser ranging and detection (LIDAR) [16].…”

Airborne quantum key distribution: a review [Invited]

“…In this configuration, the receiving side benefits from using the largeaperture telescopes to enhance the beam collection efficiency. Sophisticated and relatively bulky superconducting nanowire single-photon detectors (SNSPDs) [68,69] can also be utilized to improve the detecting efficiency of quantum signals. By utilizing the drones with a high-precision ATP system, it is also feasible to realize flexible inter-platform links, as shown in Fig.…”

Multispectral Superconducting Nanowire Single-Photon Detector Based on Thickness-Modulated Optical Film Stack

“…Since the first demonstration, various SNSPDs have been developed based on the wideband response characteristics of superconducting nanowire arising from meVlevel copper-pair energy. Conventional SNSPDs for singlewavelength applications have been manufactured in the ultraviolet-visible to mid-infrared wavelength range [3][4][5][6][7][8][9], and their development has demonstrated near-unity detection efficiencies at target wavelengths [10][11][12][13]. Meanwhile, broadband SNSPDs with high efficiencies across wide bandwidths have been developed, relying on the broadband 353248602@qq.com; xiaoyou@mail.sim.ac.cn; zhangxingyu@mail.sim.ac.cn; zwang@mail.sim.ac.cn) reflectivity of metallic mirrors or other broadband optical structures [14][15][16][17], which may be helpful for photon counting spectroscopy applications.…”