Intermodal four-wave mixing for heralded single-photon sources in the MIR (Conference Presentation)

Single photon sources by heralding time correlated photons are described. By intermodal four wave mixing (FWM) in a silicon photon circuit, we generate a herald photon at 1260 nm and the heralded one beyond 2 um, with a coincidence to accidental ratio larger than 50 and a single photon purity of 0.75. The discrete band intermodal phase matching does not require further filtering to improve the purity of the single photon. Moreover, the intermodal FWM exhibits high controllability of the signal/idler wavelengths, that can be generated far from the Raman and pump noise, with improved noise filtering.