Passive synchronization of femtosecond Er- and Yb-fiber lasers by injection locking

We demonstrated a self-starting passively synchronized Er- and Yb-fiber laser system. Synchronization was implemented by the master-slave configuration where partial output power of the Er-fiber laser was injected into the Yb-fiber laser via a 2-m-long single-mode fiber. The output pulses both were in femtosecond range, and the cavity mismatch tolerance was 160 μm, corresponding to 1267 Hz in frequency domain. The RMS (root mean square) timing jitter between these two lasers was calculated as 14.7 fs (5-kHz bandwidth) in one second.