Heralded single-photon sources (HSPS) intrinsically suffer from multiphoton emission, leading to a trade-off between the source's quality and the heralding rate. A solution to this problem is to use photon-number-resolving (PNR) detectors to filter out the heralding events where more than one photon pair is created. Here, we demonstrate the use of a high-efficiency PNR superconducting nanowire single-photon detector (SNSPD) as a heralding detector for a HSPS. By filtering out higher-order heralding detections, we can reduce the g⁽²⁾(0) of the heralded single photon by (26.6 ± 0.2)\,%, or alternatively, for a fixed pump power, increasing the heralding rate by a factor of 1.363 ± 0.004 for a fixed g⁽²⁾(0). Additionally, we use the detector to directly measure the photon-number distribution of a thermal mode and calculate the unheralded g⁽²⁾(0). We show the possibility to perform g⁽²⁾(0) measurements with only one PNR detector, with the results in agreement with those obtained by more common-place techniques which use multiple threshold detectors. Our work shows that efficient PNR SNSPDs can significantly improve the performance of HSPSs and can precisely characterize them, making these detectors a useful tool for a wide range of optical quantum information protocols.
No takes yet. Share an insight, caveat, or question.
Stasi et al. (2022) studied this question.