Tunable soliton molecules enabled by a nanotubes-based mode-locked fiber laser

Soliton molecules are fascinating phenomena in ultrafast lasers which have potential for increasing the capacity of fiber optic communication. The investigation of reliable materials will be of great benefit to the generation of soliton molecules. Herein, an all-fiber laser cavity was built incorporating carbon nanotubes-based saturable absorber. Mode-locked pulses were obtained at 1565.0 nm with a 60 dB SNR and a 4.5 W peak power. Soliton molecules were subsequently observed after increasing the pump power and tuning polarization state in the same cavity, showing variable separation of pulses between 4.87 and 25.76 ps. Furthermore, these tunable soliton molecules were verified and investigated through numerical simulation, where the tuning of pump power and polarization state were simulated. These results demonstrate that soliton molecules are promising to be applied in optical communication, where carbon nanotube-based mode-locked fiber lasers serve as a reliable platform for the generation of these soliton molecules.