Continuous-wave oscillation of thulium-sensitized holmium-doped silica fiber laser.

We have observed oscillation in a Tm(3+) and Ho(3+) codoped silica fiber from the (5)I(7) ? (5)I(8) transition of Ho(3+) in the 2-microm region, by pumping the fiber laser into a Tm(3+) absorption between 800 and 830 nm. By a change in the cavity length, the laser was tunable between 2.037 and 2.096 microm. When the laser was pumped with a Ti:sapphire laser at 820 nm, an absorbed threshold power extracted power of 214mW, a slope efficiency of 4.2%,and maximum extracted power of 12.5 mW were measured.