Towards high repetition rate operational quantum relay at telecom wavelength

Quantum entanglement, besides being a theoretical ground in quantum physics, is now considered as a key resource for the implementations of many complex quantum information science (QIS) protocols. One of the most investigated QIS protocols for long-distance quantum communication, involving entanglement as a genuine resource, is the entanglement swapping in quantum relay (QR) configuration. Alas, the quality of a QR is heavily affected by synchronization issues between remote entangled photon pair sources. In this paper, we present an all-optical, high repetition rate synchronization technique in picosecond regime, and demonstrate the realization of ultra-fast photon pair sources based on high-performance telecom components and nonlinear optics.