Thin-disk multipass amplifier emitting radially polarized beam with 635 W of average power and 2.1 mJ of pulse energy

摘要

We present our latest achievements on the amplification of ultrafast beams with radial polarization using a thin-disk multipass amplifier. Starting with a seed laser (TruMikro5050 provided by the company TRUMPF laser GmbH) delivering a linearly polarized beam with 115 W of average output power, 6.5 ps pulse duration at a repetition rate of 300 kHz, we could extract radially polarized laser pulses with an average output power of 635 W and a pulse energy of 2.1 mJ. The radial polarization was obtained by using a segmented wave-plate placed in front of the amplifier. This is, to the best of our knowledge, the highest average output power and pulse energy reported so far for radially polarized ultrafast lasers. A scheme for direct amplification of such ring-shaped radially polarized laser beams is presented together with a possible solution to compensate for the depolarizing phase shift introduced by the optical components in the amplifier.