Figure 1
(a) The schematic setup of generating the passive HSPS. The pump light is generated from a light emitting diode (LED). After passing though the Periodically Poled Lithium Niobate (PPLN) crystal, the parametric down-conversion photon pairs (idler and signal) are separated by a dichroic mirror (DM). The idler mode is split into two parts by a beam-splitter (BS) and sent into two single-photon detectors (A1 and A2) respectively. (b) The illustration of single-photon detection in the idler mode, where an imaginary beam-splitter (IBS) is positioned before each local detector. t is the IBS transmissivity.
