Hybrid mode locking of an all-fiber holmium laser

We demonstrate an all-fiber 2 μm holmium-doped laser hybrid mode locked by the co-action of nonlinear polarization evolution and absorption saturation of single-walled carbon nanotubes. The laser was pumped by a continuous-wave ytterbium-doped fiber laser at a wavelength of 1125 nm. The holmium laser generated 1.4 ps soliton pulses at a wavelength of 2082 nm with bandwidth up to 3.3 nm and repetition rate of 14.9 MHz. An average output power of 4.7 mW was obtained corresponding to pulse energy up to 0.3 nJ and peak power of 220 W.