CONTINUOUS-WAVE OSCILLATION OF THULIUM-SENSITIZED HOLMIUM-DOPED SILICA FIBER LASER

We have observed oscillation in a Tm3+ and Ho3+ codoped silica fiber f rom the 5I7 --> 5I8 transition of Ho3+ in the 2-mum region, by pumping the fiber laser into a Tm3+ absorption between 800 and 830 nm. By a c hange in the cavity length, the laser was tunable between 2.037 and 2. 096 mum. When the laser was pumped with a Ti:sapphire laser at 820 nm, an absorbed threshold power of 214 mW, a slope efficiency of 4.2%, an d maximum extracted power of 12.5 mW were measured.