Compact 2 W wavelength-tunable Er:ZBLAN mid-infrared fiber laser

We report a high-power diode-pumped wavelength-tunable (2.7-2.83 mu m) erbium-doped ZBLAN mid-infrared fiber laser. Continuous-wave output of >2 W with a spectral linewidth of 1.27 GHz was obtained. Nevertheless, the wavelength-tunable range was found to shrink with increasing pump power. The gain bandwidth narrowing under strong pumping may be ascribed to the enhanced reabsorption process and the weakened population inversion associated with shorter-wavelength emissions. (C) 2007 Optical Society of America.