Holmium thin-disk laser based on Ho:KY(WO4)2 / KY(WO4)2 epitaxy with 60% slope efficiency and simplified pump geometry

Identifier:  PC:2912

Handle: https://hdl.handle.net/20.500.11797/PC2912

Authors:  Mateos, X.; LAMRINI, S.; SCHOLLE, K.; FUHRBERG, P.; VATNIK, S.; LOIKO, P.; VEDIN, I.; Aguiló, M.; Díaz, F.; GRIEBNER, U.; PETROV, V.

Abstract:
We report on the first Holmium (Ho3+) monoclinic double tungstate thin-disk laser. It is based on a 250 µm-thick 3 at. % Ho:KY(WO4)2 active layer grown on a (010)-oriented KY(WO4)2 substrate. When pumped by a Tm-fiber laser at 1960 nm with a single-bounce (single double-pass) pump geometry, the continuous-wave Ho:KY(WO4)2 thin-disk laser generated 1.01 W at 2057 nm corresponding to a slope efficiency ¿ of 60% and a laser threshold of only 0.15 W. Implementing a double-bounce (second double-pass) for the pump, the output of this laser was scaled to 1.57 W with ¿ = 55%. The maximum stimulated-emission cross-section ¿SE of the Ho3+ ions in the epitaxial layer reaches 2.5×10-20 cm2 at 2056.5 nm for E || Nm. The Ho:KY(WO4)2 epitaxial structures are promising for multi-watt mode-locked thin-disk lasers at ~2.06 µm.© 2017 Optical Society of America