Observation of correlated-photon statistics using a single detector

Two-photon interference effects and correlated-photon statistics have traditionally been observed in the coincidence detection rate between two detectors. Here, we report observations of correlated-photon statistics, which are due to two-photon entanglement and interference, in the single-photon detection rate. The observed effects are explained by considering all possible photon number states that reach the detector, rather than considering just the state post-selected by the coincidence circuit.