Universal response curve for nanowire superconducting single-photon detectors
J. J. Renema, G. Frucci, Zili Zhou, F. Mattioli, Alessandro Gaggero, Roberto Leoni, M. J. A. de Dood, Andrea Fiore, Martin P. Van Exter · Physical Review B · 2013
Using detector tomography, we investigate the detection mechanism in NbN-based superconducting single photon detectors (SSPDs). We demonstrate that the detection probability uniquely depends on a particular linear combination of bias current and energy, for a large variation of bias currents, input energies and detection probabilities, producing a universal detection curve. We obtain this result by studying multiphoton excitations in a nanodetector with a sparsity-based tomographic method that allows factoring out of the optical absorption. We discuss the implication of our model system for the understanding of meander-type SSPDs.