Uncorrelated photon pair generation from an integrated silicon nitride resonator measured by time-resolved coincidence detection

We measure the joint temporal intensity of signal and idler photon pairs generated by spontaneous four-wave mixing in a silicon nitride microresonator by time-resolved coincidence detection. This technique can be applied to any high-Q optical cavity whose photon lifetime exceeds the duration of the pump pulse. We tailor the temporal correlation of photon pairs by using a resonant interferometric coupler, a device that allows us to independently tune the quality factors of the pump and signal and idler resonances. Temporal post-selection is used to accurately measure the temporal emission of the device, demonstrating a purity of 98.67(1)%.