Optical properties of YSAG : Yb : Er ceramics with Sc3+ cations in the dodecahedral and octahedral positions of the garnet crystal lattice

Optical ceramics based on YSAG : Yb : Er with the compositions {Y1.86Yb0.45Er0.09Sc0.6}[Al1.6Sc0.4]Al3O12 and {Y2.26Yb0.45Er0.09Sc0.2}[Al1.0Sc1.0]Al3O12 were fabricated by vacuum sintering from pre-synthesized nanocrystalline powders. A comparative analysis of these samples with optical ceramics of the compositions {Y2.34Yb0.45Er0.09Sc0.12}[Al1.92Sc0.08]Al3O12 and {Y0.96Yb0.45Er0.09Sc1.50}[Al1.8Sc0.2]Al3O12 was carried out. The influence of scandium cations in the dodecahedral and octahedral positions of the garnet crystal lattice on the refractive index of YSAG : Yb : Er, as well as the values of absorption coefficients, integral luminescent intensities, and lifetimes of excited states of Yb3+ (2F7/2 and 2F5/2) and Er3+ (4I15/2, 4I13/2, 4F9/2, and 4S3/2) cations was revealed in the wavelength ranges 520–700 nm and 890–1690 nm. It has been shown that by changing the concentrations of scandium cations in the dodecahedral and octahedral positions of the crystal lattice of YSAG : Yb : Er solid solutions, it is possible to purposefully change the efficiency of energy transfer from ytterbium cations to erbium cations.