Offset-locking-based frequency stabilization of external cavity diode lasers for long-distance quantum communication

Quantum repeaters are required for long-distance quantum communication. For efficient coupling of entangled photon sources with narrow-linewidth memories we performed the frequency stabilization two lasers at 1514 and 1010 nm. The nm pump laser source exhibited a stability 3.6 \times 10^{-12} (\tau = 1 s). wavelength conversion system 3.4 stabilities both were approximately orders magnitude smaller than width 4 MHz Pr:YSO memory. Such frequency-stabilized can realize remote memory an in repeaters.