Simple autocorrelation method for thoroughly characterizing single-photon detectors.

We introduce and demonstrate a simple and highly sensitive method for characterizing single-photon detectors. This method is based on analyzing multi-order correlations among time-tagged detection events from a device under calibrated continuous-wave illumination. First- and second-order properties such as detection efficiency, dark count rate, afterpulse probability, dead time, and reset behavior are measured with high accuracy from a single data set, as well as higher-order properties such as higher-order afterpulse effects. While the technique is applicable to any type of click/no-click detector, we apply it to two different single-photon avalanche diodes, and we find that it reveals a heretofore unreported afterpulse effect due to detection events that occur during the device reset.