Gain-switched 2.8 m fluoride fiber laser pumped at 1550 nm

We demonstrated a gain-switched heavily erbium-doped fluoride fiber laser pumped at 1550 nm. A 2.8 mu m short-pulsed laser with a maximum average output power of 350 mW and a practical optical-optical efficiency of similar to 11.3% was obtained at a repetition rate of 50 kHz with a single pulse energy of 7 mu J, a pulse width of 938 ns, and a peak power of 7.5 W. Gain-switched temporal states with 1/n (n = 4,3,2) (ratio of signal pulses per pump pulses) pump repetition rates were first observed in the 2.8 mu m erbium-doped fluoride fiber laser. These results indicate that the 1550 nm pulsed pumping scheme is an efficient and potential way for power scaling of 2.8 mu m short-pulsed erbium-doped fluoride fiber lasers.