Time-correlated photons from an In_{0.5}Ga_{0.5}P photonic crystal cavity on a silicon chip

Abstract

Time-correlated photon pairs are generated by triply resonant four-wave-mixing in an In_{0.5}Ga_{0.5}P photonic crystal cavity. Maximal efficiency is reached by actively compensating for the residual spectral misalignment of the cavity modes. The generation rate reaches 5 MHz in cavities with a Q-factor ≈4×10^{4}, more than one order of magnitude larger than what is measured using ring resonators with similar Q factors fabricated on the same chip. The photonic crystal source is integrated on a Si photonic circuit, an important asset for applications in quantum technologies.