Fig. 1. All-optical passive synchronization system for dual-color ultrafast lasers in all-polarization-maintaining architecture. (a) Er-doped fiber laser as master; (b) Er-doped fiber amplifier; (c) Yb-doped fiber laser as slave; (d) synchronized dual-color pulses

Fig. 2. Optimization and long-term stability of synchronization systems. (a) Tolerance range of cavity-length mismatch versus injection power; (b) dependence of tolerance range of cavity-length mismatch and pulse duration on FBG bandwidth in slave laser; (c) long-term stability for synchronization system

Fig. 3. Repetition rates and spectral variation of synchronization systems. (a) Repetition rates of master and slave lasers versus cavity-length mismatch; (b) dependence of optical spectra of slave laser on cavity-length mismatch