Switchable dual-wavelength conventional soliton delivered from a graphene-mode-locked fiber laser

Depending on different operation conditions, such as the pump strength and orientations of the polarization controller, the operating wavelengths of the laser can be easily changed. Besides single-wavelength, the laser is able to achieve sub-picosecond solitons at both ∼1531 nm and ∼1557 nm simultaneously. Experimental results show that the dual-wavelength CSs exhibit the same pulse durations and pulse intensities, but clearly different group velocities. This laser provides a stable and switchable dual-wavelength ultrafast-pulsed source, which is attractive for potential applications in optical communications.