High pulse energy multiwatt Yb:CaAlGdO4 and Yb:CaF2 regenerative amplifiers

We investigated and compared Yb:CaAlGdO4 and Yb:CaF2 regenerative amplifiers at repetition rates 5-10 kHz, a frequency range interesting for industrial applications requiring relatively high pulse energy. Both materials allow for pulse energies close to 1 mJ with sub-400-fs pulses. The two laser materials offer comparable performance in the pump power range investigated. The same regenerative amplifiers can be run up to 500 kHz for much faster material processing, with maximum output power of up to 9.4 W.