Short Tm3+ doped fiber lasers with watt level output near 2 μm

High-power operation of diode-pumped fiber lasers at wavelength near 2 μm are demonstrated with short length of heavily Tm3+-doped silica glass fibers. With 7-cm long fiber, a laser at near 2 μm is obtained with the threshold of 135 mW, maximum output power of 1.09 W, and slope efficiency of 9.6% wi