Wavelength dependence of intrinsic detection efficiency of NbN superconducting nanowire single-photon detector

Wang Yong^{1, 2, 3}, Li Hao^{1, 3, †}, You Li-Xing^{1, 3, ‡}, Lv Chao-Lin^{1, 2, 3}, Wang He-Qing^{1, 2, 3}, Zhang Xing-Yu^{1, 2, 3}, Zhang Wei-Jun^{1, 3}, Zhou Hui^{1, 3}, Zhang Lu^{1, 2, 3}, Yang Xiao-Yan^{1, 3}, Wang Zhen^{1, 3}

Bias current as a function of incident photon energy at a response probability of 1% (green triangle), 30% (dark triangle), 50% (blue triangle), and 80% (red triangle) for an SNSPD linewidth of 60 nm. The red lines represent the fitting curves with the equation I=I0+Ae−E/E0.