Zhang Hengbin, Liu Junku, Guo Jianghua, Xiao Lin, Xie Jun
Opt Express. 2020 May 25;28(11):16696-16707. doi: 10.1364/OE.390378.
Superconducting nanowire-based single-photon detectors (SNSPDs) are promising devices, especially with unrivalled timing jitter ability. However, the intrinsic physical mechanism and the ultimate limit of the timing jitter are still unknown. Here, we investigated the timing jitter of the SNSPD response to different excitation wavelengths from visible to near-infrared (NIR) as a function of the relative bias currents and the substrate temperature. We established a physical model based on a 1D electrothermal model to describe the hotspot evolution and thermal diffusion process after a single photon irradiated the nanowire. The simulations are in good agreement with the experimental results and reveal the other influencing factors and potential ways to further improve the timing jitter of SNSPDs. Finally, we introduce a new time-resolved approach, where by collecting the instrument response function (IRF) of SNSPDs, the wavelength of the incident photons can be easily discriminated with a resolution below 80 nm.
基于超导纳米线的单光子探测器（SNSPD）是很有前景的器件，尤其是其具有无与伦比的定时抖动能力。然而，定时抖动的内在物理机制和最终极限仍然未知。在此，我们研究了SNSPD对从可见光到近红外（NIR）不同激发波长的响应定时抖动，该抖动是相对偏置电流和衬底温度的函数。我们基于一维电热模型建立了一个物理模型，以描述单个光子照射纳米线后热点的演化和热扩散过程。模拟结果与实验结果吻合良好，揭示了其他影响因素以及进一步改善SNSPD定时抖动的潜在方法。最后，我们引入了一种新的时间分辨方法，通过收集SNSPD的仪器响应函数（IRF），可以轻松地以低于80 nm的分辨率区分入射光子的波长。
