Real-Time Photobleaching and Stable Operation at 204 mW of a Tm : ZBLAN Blue Fiber Laser

We report the observation of a stable output power of 204 mW in a Tm$^{3+}$ : ZBLAN upconversion blue fiber laser, which we believe to be the highest reported to date as being stable in the long term. For the first time, we also present results of the dynamics of a real-time photobleaching of the color centers by an external laser source during laser oscillation. The dependence of the photoinduced absorption on the photobleaching power is also investigated. The total average photoinduced absorption was estimated at 2.7 dB/m.