All-fiber wavelength-tunable Tm-doped fiber laser mode locked by SESAM with 120 nm tuning range.

We demonstrate an all-fiber widely wavelength-tunable thulium-doped fiber laser (TDFL) mode locked by a semiconductor saturable absorber mirror (SESAM). The tuning range spans 121 nm, from 1862 nm to 1983 nm. The central wavelength is tuned by a grating-based tunable filter in the ring laser cavity. To the best of our knowledge, this is so far the most widely wavelength-tunable TDFL mode locked by SESAM.