All-fiber Er-doped dissipative soliton laser based on evanescent field interaction with carbon nanotube saturable absorber

We report on an Er-doped fiber pulse laser at large net normal dispersion cavity by employing a dispersion compensating fiber in combination with a single-walled carbon nanotube (SWCNT) saturable absorber. A SWCNT/polymer composite film uniformly spin-coated on the side-polished fiber is prepared for robust and efficient nonlinear interaction with evanescent fields in the waveguide expecting increase of optical and thermal damage threshold compared to previously reported direct coating of SWCNTs on fiber ferrules. The fabricated dissipative soliton fiber laser exhibits high average output power of 55.6 mW, corresponding to pulse energy about 2.35 nJ. Highly chirped 5.8 ps pulses are generated with a spectral bandwidth of 13.9 nm and compressed down to 226 fs using additional length of conventional optical fiber at extra-cavity.