▎ 摘　　要

We propose and demonstrate a wavelength changeable thulium-doped fiber laser (TDFL) based on a monolayer graphene saturable absorber (SA). With different pump powers and polarization controller states, the laser can operate in different operation modes including continuous wave, single solitons, harmonic mode-locked pulses of 2nd to 4th order, and soliton molecules. Wavelength changing over a range of 7-11 nm for different operation regimes was realized by stretching the tapered fiber and adjusting the polarization controller in the cavity. To the best of our knowledge, this is the first TDFL that is changeable in wavelength under different operation modes and that is based on a monolayer graphene SA.