Multi-State Solitons in Multi-Wavelength Er-Doped Fiber Laser

In this paper, we report on the emission of composite-state solitons from multi-wavelength mode-locked Er-doped fiber laser based on nonlinear polarization rotation (NPR) technique. The optical spectrum exhibits three distinct spectral peaks centered at 1567 nm, 1585 nm, and 1616 nm, with coexisting soliton patterns observed on the oscilloscope (each is associated with one wavelength in the triple-wavelength spectrum). By fine adjustment of the polarization controllers, this complex regime can be switched into harmonic states. This work introduces new study to the composite-state soliton regime generated from multi-wavelength lasing.