All-solid-state 5-kHz 0.2-TW Ti:sapphire laser system.

We have developed an all-solid-state 5-kHz Ti:sapphire laser system, which produces 22-fs, 0.2-TW pulses. An average power of 22.2 W is the highest ever obtained in ultrashort laser sources. The serious thermal lensing due to high power pumping in a small area of the Ti:sapphire crystal is controlled successfully by a stable quasi-cavity with two concave mirrors.