High-average-power picosecond Yb-doped fiber amplifier

We report on a cladding-pumped, ytterbium-doped large-core-area fiber amplifier that is capable of generating 51.2 W of average power at a 1064-nm center wavelength, an 80-MHz repetition rate, and a 10-ps pulse duration. In an ytterbium-doped large-mode-area fiber these pulses could be amplified up to 43.2 W with diffraction-limited beam quality (M-2 similar to 1.3). Power scaling limitations that arise from nonlinear distortions such as self-phase modulation and stimulated Raman scattering are discussed. (C) 2001 Optical Society of America.