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}

Plot of bias current versus incident photon energy at 1% response probability for wire widths of 30 nm, 80 nm, 100 nm, and 140 nm. Both the experimental data and the fitting curves (red lines) follow a nonlinear energy–current relation. The fitting parameters are I0=1.6μA, 2.2μA, 3.9μA, 9.7μA; A=0.7μA, 10.6μA, 14.4μA, 10.7μA; and E0=0.5eV, 1.0 eV, 0.8 eV, 0.7 eV, respectively.