We demonstrate and verify quantum detector tomography of a superconducting nanowire single-photon detector (SNSPD) in a multiplexing scheme which permits measurement of up to 71000 photons per input pulse. We reconstruct the positive operator valued measure (POVM) of this device in the low photon-number regime, and use the extracted parameters to show the POVMs spanning the whole dynamic range of the device. We verify this by finding the mean photon number of a bright state. Our work shows that a reliable quantum description of large-scale SNSPD devices is possible, and should be applicable to other multiplexing configurations.
@article{arxiv.2102.11596,
title = {Quantum detector tomography of a high dynamic-range superconducting nanowire single-photon detector},
author = {Timon Schapeler and Jan Philipp Hoepker and Tim J. Bartley},
journal= {arXiv preprint arXiv:2102.11596},
year = {2021}
}