Temporal ghost imaging for quantum device evaluation.

Ghost imaging (GI) can reconstruct the image of an object by measuring the correlation function of two beams, none of which carries the structure information of the object independently. This powerful technology makes it possible to obtain high-quality imaging of the object even in the presence of noise. Here, we introduce the GI method into quantum device evaluation in the time domain. We realized a proof-of-principle experiment to evaluate the temporal detection efficiency of a gated-mode single-photon avalanche detector (SPAD). The experimental results show that high-quality evaluation of temporal characteristics of the SPAD can be realized by the method of temporal GI (TGI). Our work indicates that the TGI method is an effective tool to monitor the temporal characteristics of quantum devices in real time and will bring a new perspective to the security evaluation of quantum communication.