Heralded single-photon source fueled by light-emitting diode

An attempt is made to generate a stream of heralded single photons using spontaneous parametric downconversion (SPDC) in type-II β-barium borate (BBO) pumped by a fiber-coupled light-emitting diode (LED). The hallmark interlocked circles develop only after removing the fluorescence background without correlation with pump polarization during spatial mode mapping of SPDC photons that allows otherwise diffuse circles to be projected distinctly in the image plane as photons with an identical wave vector from across the output area of BBO are collectively focused. Time-gating reveals a clear signature of photon antibunching, which promises a heralded single photon source fueled by commercially available LEDs.