Superconducting nanowire single-photon detectors are widely used for detecting individual photons across various wavelengths from ultraviolet to near-infrared range. Recently, there has been increasing interest in enhancing their sensitivity to single photons in the mid-infrared spectrum, driven by applications in quantum communication, spectroscopy, and astrophysics. Here, we present our efforts to expand the spectral detection capabilities of U-shaped NbTiN-based superconducting nanowire single-photon detectors, fabricated in a 2-wire configuration on a silicon-on-insulator substrate, into the mid-infrared range. We demonstrate saturated internal detection efficiency extending up to a wavelength of 3.5 μm for a 5 nm thick and 50 nm wide NbTiN nanowire with a dark count rate less than 10 counts per second at 0.9 K and a rapid recovery time of 4.3 ns. The detectors are engineered for integration on waveguides in a silicon-on-insulator platform for compact, multi-channel device applications.

中文翻译：

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绝缘体上硅上 NbTiN 超导纳米线单光子探测器的中红外表征


超导纳米线单光子探测器广泛用于检测从紫外到近红外范围的各种波长的单个光子。最近，在量子通信、光谱学和天体物理学应用的推动下，人们对提高它们对中红外光谱中单光子的灵敏度越来越感兴趣。在这里，我们介绍了我们将基于 U 形 NbTiN 的超导纳米线单光子探测器的光谱探测能力扩展到中红外范围的努力，该探测器在绝缘体上硅衬底上以 2 线配置制造。我们证明了 5 nm 厚和 50 nm 宽的 NbTiN 纳米线的饱和内部检测效率扩展到 3.5 μm 的波长，在 0.9 K 时暗计数率小于每秒 10 计数，快速恢复时间为 4.3 ns。这些探测器设计用于集成在绝缘体上硅平台中的波导上，适用于紧凑的多通道设备应用。