超导纳米线本征光谱响应特性及多光谱器件研究

近年来超导纳米线单光子探测器（SNSPD）因高探测效率、低暗计数，低时间抖动，高探测速度等特点受到广泛关注，并在量子信息等前沿领域发挥了重要作用。尽管如此，超导纳米线宽谱光子响应能力却并未有效发挥，同时其背后的物理机制依然模糊不清。本项目将探究超导纳米线光谱响应特性及机制，研制多光谱SNSPD——基于单一器件实现多个光谱范围的高效单光子探测。针对性探究满足纳米线本征光谱响应特性的物理机制，重点通过光子能量-偏置电流响应关系佐证理论模型，提出相应光谱探测范围的超导纳米线设计准则。同时，基于已有多光谱器件研究基础，利用双层或多层超导纳米线架构、光学薄膜多腔级联或厚度调制等技术手段，实现新型多光谱器件。本项目有望阐明超导纳米线光谱响应特性及机理，缓解或突破传统SNSPD的带宽和效率的约束关系，对于单光子探测科学原理及技术应用具有重要意义。

Superconducting nanowire single photon detectors (SNSPDs) have attracted considerable attention in recent years due to their high detection efficiency, low dark count, low timing jitter and high speed, enabling numerous applications in frontier fields such as quantum information technology. However, the wideband photon response characteristic has not been effectively utilized and the underlying physics is still unclear. In this project, the detection mechanism is mainly investigated and multispectral SNSPD is developed that can simultaneously detect photons at well-separated wavelengths. The model that coincides with the spectral-response feature of superconducting nanowire is verified using the photon energy-current relation, based on which the nanowire design rule is proposed. Meanwhile, novel detectors are developed on the basis of our related research by employing the bilayer nanowires, optical film based cascaded cavity and thickness modulation technology. This work is of important scientific significances and application values and expected to clarify the spectral response properties and the mechanism of superconducting nanowire, and break through the limitation between responding band and efficiency of conventional detectors.