30 W dual active element Yb:KGW regenerative amplifier for amplification of sub - 500fs pulses

摘要

We report on dual active element Yb:KGW regenerative amplifier that provides ultrashort pulses in the 0.3 mJ range at high repetition rates. Each active element was pumped by two 50 W diode pump modules at 980 nm. 30W average power was obtained at 100 kHz repetition rate. Measured spectrum width of 5,4 nm allows for compression of amplified pulses to sub-300 fs pulse duration. As output power increases above 15 W nearly symmetrical Gaussian profile beam becomes slightly elliptical, although remains Gaussian in transverse directions. The measured beam quality parameter M2 is below 1,5 even at maximum output power.