Within the EU-funded project RAZipol (www.razipol.eu) the IFSW has demonstrated a multi-pass thin-disk laser amplifier generating record output powers for beams with cylindrical (radial or azimuthal) polarization, known to be advantageous for efficient laser material processing.
The used setup resulted from the project T4nPV funded by the German Ministry for Education and Research (BMBF). The modified system now delivers radially polarized ultrashort laser pulses with an average output power of 635W and a pulse duration of approximately 8 ps at a repetition rate of 300 kHz, corresponding to a pulse energy of 2.1 mJ. A TruMicro5050 (with 115 W of output power and 6.5 ps pulse duration), provided by TRUMPF Laser GmbH, was used as seed source. Its linearly polarized beam was first converted to cylindrical polarization and then folded 20 times over a thin-disk laser crystal by means of an array of 40 mirrors.
Further details on the experiments are given in A. Loescher et al., "Radially polarized emission with 635 W of average power and 2.1 mJ of pulse energy generated by an ultrafast thin-disk multipass amplifier" Opt. Lett. 40(24), 5758-5761 (2015).
Contact: Dr. Marwan Abdou Ahmed