Different operation states of passive synchronization between a 1.03 µm single-pulse and a 1.56 µm bound-soliton mode-locked fiber lasers

Techniques of passive synchronization based on cross phase modulation (XPM) effects have been successfully demonstrated for precisely locking the pulse repetition rates of mode-locked lasers at different wavelengths. Recently it has been experimentally shown that a 1.56 µm bound-soliton mode-locked Er-fiber laser can be passively synchronized to a 1.03 µm single-pulse mode-locked Yb-fiber laser by co-sharing a common fiber section [1], despite of the widely separated laser wavelengths. In this work we further investigate the underlying mechanisms and experimentally demonstrate for the first time the different operation states of passive synchronization under this type of laser systems.