Synchronized network source of indistinguishable photons

We build a network source of indistinguishable photons, synchronized to an external clock, that could be used as scalable modular unit in an extended quantum network infrastructure. We characterize the indistinguishability and synchronization of this source. The Hong-Ou-Mandel dip shows near unity indistinguishability. Allan deviation analysis shows sub-picosecond jitter when locked to an external clock. The jitter figure is more than 10 times smaller than the pulse duration of 30ps. The source is compatible with many clock recovery systems, including the White Rabbit Precision Time Protocol (WR-PTP). This source enables scalable quantum protocols over multi-node, long-distance optical networks.