Hybrid mode-locked fiber laser based on NALM and SWCNT saturable absorber

A hybrid mode-locked Er-doped fiber laser based on single-walled carbon nanotube saturable absorber and nonlinear amplifying loop mirror (NALM) is constructed. At 1564.5 nm, the mode-locked laser is self-started by carefully adjusting the polarization controller, with the repetition frequency of 16.24 MHz, 3-dB spectral width of 8.5 nm and pulse width of 302 fs. Compared with the laser only utilizing single-wall carbon nanotube saturable absorber or NALM mode-locked Er-doped fiber laser, the hybrid one has narrower output pulse width and the mode-locking state is more stable.