Estimating the indistinguishability of heralded single photons using second-order correlation

Integrated quantum photonics is a promising strand of research that involves guiding light in submicron scale structures and utilizing the quantum properties of the fundamental particle of light the photon. One of these quantum properties, the indistinguishability of the photons, is used to achieve high visibility quantum interference, which is one of the key resources in photonic quantum information processing. Here, we have demonstrated that the faster and simpler heralded and unheralded second-order correlation functions (g(2)) estimate well the visibility (indistinguishability) without performing laborious and time-consuming quantum interference measurements.