Vector Soliton Generation in a Tm Fiber Laser

Vector soliton generation is experimentally demonstrated in an all-fiber Tm/Ho-doped fiber laser operated at 1951 nm. To the best of our knowledge, it is the first clear evidence of group-velocity-locked vector soliton formation around 2 μm. Numerical simulation well reproduces the experimental observation and suggests that the central wavelength shift between the two orthogonal polarized components of the vector soliton is determined by the cavity birefringence. The central wavelength shift increased with the increasing of the cavity birefringence. However, the vector solitons become linearly polarized if the cavity birefringence is too strong. Experimental observation and numerical simulations both suggest that the vector soliton generation is wavelength independent.