Regenerative Yb:KLuW thin disk amplifier

Abstract

Ytterbium doped monoclinic double tungstates, like Yb:KYW or Yb:KGW, are attractive gain media for ultrafast laser and amplifier systems, respectively. This is owing to the high absorption and emission cross-section peaks and the broad emission bandwidth. They have proven their potential in diode-pumped high-power systems, profiting from the small quantum defect [1] and a reduced thermal load. In comparison to the above mentioned two materials, the relatively new crystal Yb:KLuW has not been investigated that intensively so far. Most of the relevant properties are very similar and the fluorescence lifetime is about 20 % longer. Compared to Yttrium and Gadolinium the ionic radius of Lutetium is closest to the one of Ytterbium and allows higher doping concentrations or lower stress in the crystal structure for similar doping levels, making it preferable for the thin disk concept. Efficient ultra short pulse laser oscillators have been demonstrated with Yb:KLuW [2, 3].