Radially Polarized Ceramic Yb:Lu2O3 Thin-Disk Laser

In this contribution, we present the generation of the radially polarized beam with polycrystalline Yb-doped lutetium oxide (Yb:Lu 2 O 3 ) as a gain medium in a thin-disk laser geometry operated in continuous-wave. Cylindrical vector beams, and in particular radially or azimuthally polarized beams, are known to be used in material processing in order to increase processes efficiency for cutting, drilling and welding [1], [2]. Compared to Yb:YAG, Yb:Lu 2 O 3 exhibit broader emission bandwidth [3] of 13 nm, which makes it suitable for the generation of ultrashort pulses (<100 fs), and higher thermal conductivity [4] of 12 W/mK allowing for high-power scaling thanks to a more efficient heat removal. Furthermore, it is easier to produce polycrystalline Yb:Lu 2 O 3 ceramics compared to single crystals due to the lower melting temperature of 1700°C [5]. An additional advantage of ceramics is that, thanks to their manufacturing process, the crystals are less exposed to tensions, therefore, exhibiting lower depolarization losses.