High-energy, high-power ytterbium-doped Q-switched fiber laser

We report on a Q-switched, cladding-pumped, ytterbium-doped large-mode-area fiber laser operating at 1090nm that is capable of generating 2.3mJ of output pulse energy at a 500Hz repetition rate and more than 5W of average output power at higher repetition rates in a high-brightness beam M2 = 3. Using a similar fiber with a smaller core, we generated 0.5 mJ pulses in a diffraction-limited beam. Our results represent a threefold increase in pulse energy over previously published values for Q-switched fiber lasers and firmly establish fiber lasers as compact, multiwatt, multi-millijoule pulse sources with large scope for both industrial and scientific applications