Narrow-linewidth fiber laser operating at 1.55 microm

We report the fabrication and operation of an Er(3+)-doped silica single-mode fiber laser operating at 1.55 microm and using a distributed fiber grating to provide feedback. The output bandwidth was measured as 0.04 nm, significantly narrower than the conventional cavity design. The laser had a threshold of 13 mW and a slope efficiency of 5%.