高性能超导相变边缘单光子探测器(特邀)  

High-performance Superconducting Transition-edge Single-photon Detectors(Invited)

作　　者：李佩展 钟家强[1] 张文[1] 王争[1] 耿悦 姚骑均[1] 缪巍[1] 任远[1] 李婧[1] 史生才[1] LI Peizhan;ZHONG Jiaqiang;ZHANG Wen;WANG Zheng;GEN Yue;YAO Qijun;MIAO Wei;REN Yuan;LI Jing;SHI Shengcai(Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China;University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院紫金山天文台,南京210023 [2]中国科学技术大学天文与空间科学学院,合肥230026

出　　处：《光子学报》2023年第5期1-9,共9页Acta Photonica Sinica

基　　金：国家重点研发计划(Nos.2017YFA0304003,2020YFC2201703);国家自然科学基金(Nos.U1831202,U1731119,U1931123,11773083,11873099);中科院项目(Nos.XPB2303,QYZDJ-SSWSLH043,GJJSTD20180003);江苏省333工程(No.BRA2020411)。

摘　　要：研究了钛膜的特性及调控机制,通过烘烤后处理工艺分析了临界温度随烘烤时间和烘烤温度的变化关系,发现临界温度随烘烤时间对数降低,但是随烘烤温度指数降低。拓展了二流体模型提取了超导相变边缘单光子探测器的温度灵敏度系数和电流灵敏度系数,并结合脉冲响应得到了器件的热容,进一步理论计算了能量分辨率对器件临界温度的依存性。最终,在器件制备过程中集成光学腔体,在1550 nm波长的光子吸收效率接近100%。研制的超导相变边缘单光子探测器系统探测效率超过90%,能量分辨率约为0.5 eV,可分辨至少10个1550 nm光子,满足快速时变天体的观测需求。Superconducting Transition-edge Sensor(TES)is a thermal detector that measures the deposited energy by changing the superconducting film's resistance.Superconducting TES-based singlephoton detectors with high detection efficiency,low dark count rate,photon-number and arriving-time resolving capability,are ideal detectors for faint and rapidly varying sources,playing a unique role in studying pulsars,neutron stars,white dwarfs and exoplanets.The critical temperature(T_(C))is the key parameter that determines the energy resolution(ΔE_(FWHM))of superconducting TES single-photon detectors,which can be finely tuned by baking the superconducting film or fabricated devices in the air.We studied the characteristics of titanium and titanium/gold bilayer films and the dependence of T_(C) on baking time(t_(baking))and baking temperature(T_(baking)).It was found that the T_(C) is logarithmically decreased with t_(baking) for a fixed T_(baking),while it is exponentially decreased with T_(baking) for a fixed t_(baking).By treating the phaseslip parameters as variables,we extended the two-fluid model to extract the key parameters of superconducting TESs including temperature and current sensitivity coefficients from the measured currentvoltage curves at different bath temperatures.By adding an M factor to take the excess noise into account,the simulated ΔE_(FWHM) is consistent with the measured one.We then calculated the T_(C) dependence of ΔE_(FWHM) for a 20μm×20μm Ti TES device and found that superconducting TESs with a T_(C) of less than 170 mK can easily discriminate the photon numbers with a good ΔE_(FWHM).Finally,we designed and fabricated titanium-based superconducting TES single-photon detectors,which were embedded in an optical cavity to improve the absorption efficiency.The optical cavity is composed of a dielectric mirror with 8 periods of Ta_(2)O_(5)/SiO_(2) layers and an anti-reflection coating with 2 periods of Ta_(2)O_(5)/SiO_(2) layers.The refractive index of Ta_(2)O_(5),SiO_(2) and titanium film were mea

关 键 词：相变边缘探测器 单光子探测 能量分辨率 量子效率 

分 类 号：O43[机械工程—光学工程]