High average power sub-picosecond pulse generation at 515 nm by extracavity frequency doubling of a mode-locked Innoslab MOPA

More than 370 W average power at 515 nm were achieved by frequency doubling of sub-picosecond pulses of an Innoslab based Yb:YAG MOPA system. At 50 MHz repetition rate this corresponds to a pulse energy of 7 µJ in the green. The pulse duration of 680 fs and the transformation limit of the infrared source could be maintained, thus the laser provides more than 10 MW pulse power. The beam quality at 280 W was M2 < 1.4, at more than 370 W it was measured as M2 < 1.7. Extensive numerical modeling was applied to design the conversion stage.