LAUSR

We demonstrated a high average power dual-crystal Yb:CALGO regenerative amplifier(RA) operated in TEM00 mode. The dual-crystal configuration effectively mitigated thermal effects and enabled a continuous output power of 42.5 W at a pump power of 160 W with the central wavelength of 1054 nm. During regenerative amplification, an amplified output power of 38 W was obtained at repetition rates ranging from 50 to 200 kHz, the central wavelength of 1043 nm while a compressed pulse width of 290.8 fs. Benefiting from effective thermal management and the thermal insensitive cavity, a near-diffraction-limited beam quality was measured to be Mx2 = 1.11 and My2=1.11 at the highest output power.