基于超导原理的超导纳米线单光子探测器(superconducting nanowire single photon detector,SNSPD)以其在高量子效率、高计数率、低暗计数和低时间抖动等方面的优势引起广泛的研究。综述了SNSPD的物理模型和研究进展。首先从第一次在实...基于超导原理的超导纳米线单光子探测器(superconducting nanowire single photon detector,SNSPD)以其在高量子效率、高计数率、低暗计数和低时间抖动等方面的优势引起广泛的研究。综述了SNSPD的物理模型和研究进展。首先从第一次在实验上发现超导铅薄膜的电热效应出发讲述了SNSPD的起源。然后从SNSPD进行单光子探测的物理过程出发详细分析了SNSPD的单光子探测机制,并分别根据电热模型和唯象模型对探测机制进行了详细的物理解释。紧接着,详细阐述了量子效率分析模型,指出SNSPD的系统量子效率由本征量子效率、耦合效率和光吸收效率三部分组成。最后,从如何提高入射光子与SNSPD的耦合效率、如何提高光子吸收效率、如何提高SNSPD本征量子效率、研究基于新型材料的SNSPD、如何实现光子数分辨和对光子偏振态不敏感的SNSPD、以及研究SNSPD的噪声机制以减小暗计数和时间抖动等方面详细列举了目前各小组研究SNSPD所取得的最新进展。展开更多
In this paper,a sliding mode control with perturbation estimation(SMCPE) coupled with an inverse hysteresis compensator is proposed for the motion tracking control of a microposition system with piezoelectric actuatio...In this paper,a sliding mode control with perturbation estimation(SMCPE) coupled with an inverse hysteresis compensator is proposed for the motion tracking control of a microposition system with piezoelectric actuation.The inverse hysteresis compensator is employed to cancel the hysteresis nonlinearity,thus reducing the nonlinear system to a linear system with an inversion error.Then,a SMCPE controller is adopted to deal with all the unmodeled dynamics and disturbances,aiming at improving the dynamic performance and the robustness of system.An experiment of a piezoelectric actuator is presented to demonstrate the feasibility and effectiveness of the proposed control scheme.The result shows that for a fast-rate control input,the proposed method is capable of leading to a good performance of system behavior.展开更多
文摘基于超导原理的超导纳米线单光子探测器(superconducting nanowire single photon detector,SNSPD)以其在高量子效率、高计数率、低暗计数和低时间抖动等方面的优势引起广泛的研究。综述了SNSPD的物理模型和研究进展。首先从第一次在实验上发现超导铅薄膜的电热效应出发讲述了SNSPD的起源。然后从SNSPD进行单光子探测的物理过程出发详细分析了SNSPD的单光子探测机制,并分别根据电热模型和唯象模型对探测机制进行了详细的物理解释。紧接着,详细阐述了量子效率分析模型,指出SNSPD的系统量子效率由本征量子效率、耦合效率和光吸收效率三部分组成。最后,从如何提高入射光子与SNSPD的耦合效率、如何提高光子吸收效率、如何提高SNSPD本征量子效率、研究基于新型材料的SNSPD、如何实现光子数分辨和对光子偏振态不敏感的SNSPD、以及研究SNSPD的噪声机制以减小暗计数和时间抖动等方面详细列举了目前各小组研究SNSPD所取得的最新进展。
基金supported by National Science Foundation of China under Grant No.61304097Foundation for Innovative Research Groups of the National Natural Science Foundation of China under Grant No.61321002Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT1208
文摘In this paper,a sliding mode control with perturbation estimation(SMCPE) coupled with an inverse hysteresis compensator is proposed for the motion tracking control of a microposition system with piezoelectric actuation.The inverse hysteresis compensator is employed to cancel the hysteresis nonlinearity,thus reducing the nonlinear system to a linear system with an inversion error.Then,a SMCPE controller is adopted to deal with all the unmodeled dynamics and disturbances,aiming at improving the dynamic performance and the robustness of system.An experiment of a piezoelectric actuator is presented to demonstrate the feasibility and effectiveness of the proposed control scheme.The result shows that for a fast-rate control input,the proposed method is capable of leading to a good performance of system behavior.
