超导纳米线单光子探测器偏置电源系统设计

Design of high-accuracy bias power supply system for SNSPD

摘要:

超导纳米线单光子探测器(SNSPD)是一种新型的单光子探测器，相对于传统的半导体单光子探测器件，具有高计数率、低暗计数等明显优势，然而SNSPD需要在接近临界状态的偏置条件下和多个模块配合才能触发热点效应。本文设计了一种NbN材料的超导纳米线单光子探测实验系统用的偏置电源系统，辅助功能是温度控制和信号调理。实验表明，4个通道可以独立稳定输出精确度为0.1 μA且0~99.9 μA区间可调的恒流偏置，温度测量的精确度为0.05 K，热点效应产生的脉冲信号被调理后成功地被分析仪器检测到，满足单光子探测的要求。

Abstract:

Single Photon Detector(SPD) is a kind of instrument with ultra-low noise and extremely high sensitivity. It is able to detect and count the smallest energy quantum-photon, to realize the detection of weak signal. Superconducting Nanowire Single Photon Detector(SNSPD) is one of new type SPDs, which has many advantages over traditional SPD, including high count rate, low dark counts and so on. However, it is only when SNSPD runs at critical state on bias mode and works with many other modules that could trigger hotspot effect. In this paper, a bias power supply system is designed for the experimental system of SNSPD based on superconducting characteristics of NbN, coupled with functions of temperature control and signal conditioning. Experiment shows that stable parallel constant current biases can be output from four channels with a precision of 0.1 μA, a range from 0 to 99.9 μA, and temperature precision of 0.05 K; and pulses generated by hotspot effect are regulated through signal conditioning and then detected successfully by analytical instrument, which can meet the requirements of single photon detection.