Wollman E E, Verma V B, Beyer A D, Briggs R M, Korzh B, Allmaras J P, Marsili F, Lita A E, Mirin R P, Nam S W, Shaw M D
Opt Express. 2017 Oct 30;25(22):26792-26801. doi: 10.1364/OE.25.026792.
For photon-counting applications at ultraviolet wavelengths, there are currently no detectors that combine high efficiency (> 50%), sub-nanosecond timing resolution, and sub-Hz dark count rates. Superconducting nanowire single-photon detectors (SNSPDs) have seen success over the past decade for photon-counting applications in the near-infrared, but little work has been done to optimize SNSPDs for wavelengths below 400 nm. Here, we describe the design, fabrication, and characterization of UV SNSPDs operating at wavelengths between 250 and 370 nm. The detectors have active areas up to 56 μm in diameter, 70 - 80% efficiency at temperatures up to 4.2 K, timing resolution down to 60 ps FWHM, blindness to visible and infrared photons, and dark count rates of ∼ 0.25 counts/hr for a 56 μm diameter pixel. These performance metrics make UV SNSPDs ideal for applications in trapped-ion quantum information processing, lidar studies of the upper atmosphere, UV fluorescent-lifetime imaging microscopy, and photon-starved UV astronomy.
对于紫外波长的光子计数应用，目前尚无探测器能同时具备高效率（> 50%）、亚纳秒级定时分辨率和亚赫兹暗计数率。在过去十年中，超导纳米线单光子探测器（SNSPD）在近红外光子计数应用方面取得了成功，但在优化用于波长低于400 nm的SNSPD方面所做的工作很少。在此，我们描述了工作波长在250至370 nm之间的紫外SNSPD的设计、制造和表征。这些探测器的有源区直径可达56 μm，在温度高达4.2 K时效率为70 - 80%，定时分辨率低至60 ps半高宽，对可见光和红外光子不敏感，对于直径为56 μm的像素，暗计数率约为0.25次计数/小时。这些性能指标使紫外SNSPD成为捕获离子量子信息处理、高层大气激光雷达研究、紫外荧光寿命成像显微镜以及光子匮乏的紫外天文学等应用的理想选择。
