High average power ultra-fast fiber chirped pulse amplification system

We report on a high-gain diode-pumped ytterbium-doped fiber-amplifier syste m delivering pulse energies in the 100-muJ range at high repetition rates ( 32 kHz) with nearly diffraction-limited beam quality (M-2 similar to 1.7) a t a 1060-nm center wavelength. Femtosecond seed-laser pulses are stretched in a commercially available single-mode fiber and compressed after amplific ation to subpicosecond pulse duration. In a multimode Yb-doped fiber amplif ier we have demonstrated average powers of up to 22 W and single-pulse ener gies of up to 130 muJ.