Schapeler Timon, Philipp Höpker Jan, Bartley Tim J
Opt Express. 2020 Oct 26;28(22):33035-33043. doi: 10.1364/OE.404285.
We demonstrate quantum detector tomography of a commercial 2×2 array of superconducting nanowire single photon detectors. We show that detector-specific figures of merit including efficiency, dark-count and cross-talk probabilities can be directly extracted, without recourse to the underlying detector physics. These figures of merit are directly identified from just four elements of the reconstructed positive operator valued measure (POVM) of the device. We show that the values for efficiency and dark-count probability extracted by detector tomography show excellent agreement with independent measurements of these quantities, and we provide an intuitive operational definition for cross-talk probability. Finally, we show that parameters required for the reconstruction must be carefully chosen to avoid oversmoothing the data.
我们展示了一款商用2×2阵列超导纳米线单光子探测器的量子探测器断层扫描。我们表明，包括效率、暗计数和串扰概率在内的特定于探测器的品质因数可以直接提取，而无需借助基础探测器物理原理。这些品质因数可直接从该器件重构的正算子值测量（POVM）的仅四个元素中识别出来。我们表明，通过探测器断层扫描提取的效率和暗计数概率值与这些量的独立测量结果显示出极佳的一致性，并且我们为串扰概率提供了直观的操作定义。最后，我们表明必须仔细选择重构所需的参数，以避免过度平滑数据。
