Experimental and theoretical investigations of a tunable dissipative soliton fiber laser

A tunable dissipative soliton fiber laser based on carbon nanotubes and the nonlinear polarization rotation (NPR) technique has been investigated experimentally and numerically for the first time to the author's best knowledge. The laser proposed delivers strongly chirped solitons with pulse duration of ∼220 ps and a spectral width of ∼5.6 nm. With the NPR-related filtering effect, the output pulses are wavelength tunable over the range from 1566 to 1593 nm by adjusting the polarization controller (PC). Numerical results are in good agreement with experimental observations and clearly reveal that the tunable mode-locking operation is attributed to the variation of phase delay caused by the PCs.