Numerical and experimental study of gain narrowing in ytterbium-based regenerative amplifiers

We present results of gain narrowing and gain-shifting simulation in a broad-band Yb/sup 3+/-doped material during regenerative amplification process. Results of our new model are confronted with experimental results of a directly diode-pumped Yb/sup 3+/:SrY/sub 4/(SiO/sub 4/)/sub 3/O regenerative amplifier which produced 380-fs 1065-nm pulses. Thanks to a Dazzler pulse shaper, this amplifier produced estimated sub-300-fs pulses after compression.