Compact Yb:YAG crystal fiber CPA for fiber laser oscillator

We present results of experimental investigation of chirped pulse amplification (CPA) in a single and double-pass Yb:YAG single crystal fiber amplifier seeded with fiber laser pulses of ~ 200 ps, 3.8 nm FWHM and over 300 mW average power at 100 kHz. High brightness fiber coupled laser diodes of 50 and 70 W power at 940 nm were used in a single and dual end-pumping geometry.