Figure-of-eight bismuth doped fiber laser operating at 1.3 microns in dissipative soliton regime

An all-fiber ultrafast dissipative soliton laser at 1.3 microns based on phoshosilicate fiber doped with bismuth is presented. A nonlinear optical loop mirror containing high-germanium fiber with high nonlinearity and large positive dispersion was used. The scheme yields 11.3 ps pulses with energy of 1.7 nJ at repetition rate of 3.5 MHz. By means of bismuth-doped fiber amplifier and diffraction gratings compressor, the pulses were amplified up to 8.5nJ and compressed down to 530 fs. To achieve best results the optimal bismuth active fiber was chosen according to the investigated dependence of the gain coefficient on bismuth active centers concentration in phosphosilicate fibers.