Ln3+:KLu(WO4)2/KLu(WO4)2 epitaxial layers: Crystal growth and physical characterisation

Monoclinic epitaxial layers of single doped KLu1−xLnx(WO4)2 (Ln3+ = Yb3+ and Tm3+) have been grown on optically passive KLuW substrates by liquid phase epitaxy (LPE) technique using K2W2O7 as solvent. The ytterbium content in the layer is in the range of 0.05 < x < 0.75 atomic substitution and the studied thulium concentrations are 0.05 < x < 0.10. The grown epitaxies are free of macroscopic defects and only in highly ytterbium-doped epilayers do some cracks or inclusions appear. The refractive indices of the epilayers were determined. The absorption and emission cross sections of ytterbium and thulium in KLuW are characterised and laser generation results are presented and discussed.