210-W thin-rod Yb:YAG picosecond laser at 100 kHz repetition rate

A high-average-power, mJ-class picosecond laser featuring a fiberized front-end and multi-stage thin-rod Yb:YAG amplifiers is presented. Seed pulses centered at 1030 nm from a mode-locked oscillator were temporally stretched and pulse-picked to 100 kHz. In the thin-rod amplifiers, the output power was scaled to 264 W, from which a linearly polarized power of 240 W was obtained after filtering out the depolarized component. After grating compression, an average power of 210 W was achieved with a pulse energy of 2.1 mJ and a pulse duration of 1.3 ps. The beam quality factors of the compressed beam were measured to be Mx2 = 1.41 and My2 = 1.35, respectively. To the best of our knowledge, this is the first demonstration of the simultaneous achievement of over 200 W average power and 2 mJ pulse energy from a thin-rod Yb:YAG picosecond laser system.