We investigate the performance of a single-element superconducting single-photon detector (SSPD) for quantum state reconstruction. We perform quantum state reconstruction, using the measured photon counting behavior of the detector. Standard quantum state reconstruction assumes a linear response; this simple model fails for SSPDs, which are known to show a nonlinear response intrinsic to the detection mechanism. We quantify the photon counting behavior of the SSPD by a sparsity-based detector tomography technique and use this to perform quantum state reconstruction of both thermal and coherent states. We find that the nonlinearities inherent in the detection process enhance the ability of the detector to do state reconstruction compared to a linear detector with similar efficiency for detecting single photons.

• Received 22 June 2012

DOI:https://doi.org/10.1103/PhysRevA.86.062113