In our paper we demonstrate the first quantum detector tomography of a commercial 2x2 array of superconducting nanowire single photon detectors. We are able to extract detector-specific figures of merit including efficiency, dark-count and cross-talk probabilities form merely four elements of the reconstructed positive operator valued measure (POVM) of the device and without recourse to the underlying detector physics. The extracted figures of merit show excellent agreement with independent measurements of these quantities. Finally, we provide an intuitive operational definition for cross-talk probability and we show that parameters required for the reconstruction must be carefully chosen to avoid oversmoothing the data.
The paper is available at:
Timon Schapeler, Jan Philipp Höpker, and Tim J. Bartley, "Quantum detector tomography of a 2×2 multi-pixel array of superconducting nanowire single photon detectors," Opt. Express 28, 33035-33043 (2020)