Transparent Gd3Al2Ga3O12 nanocrystals/glass system: Al2O3 enhanced photoluminescence and optical nonlinearity

Abstract

Nanocrystals doped transparent materials have shown promising enhanced optical absorption and luminescence properties. In this study, we report the in-situ crystallization of Gd3Al2Ga3O12 in tellurite glass under the modification of Al2O3, and the influence on glass network structure and optical performances as a function of the size, coordination states, crystal structure, and defects of nanocrystals Gd3Al2Ga3O12 garnet (GAGG). 10-20 nm-cubic Gd3Al2Ga3O12 (Ia3d space group) nanocrystals formed in glass whose size increased with the Al2O3 content. Due to the existence of nanocrystals Gd3Al2Ga3O12, Sm3+ containing glass showed enhanced 9 absorption bands due to electron transitions of activator ions. In addition, Al2O3-activated GAGG crystallization decreased the Eg of glass, resulting in greatly improved red luminescence at 600 nm. The CIE chromaticity diagram revealed good luminescence stability. The polarizability was significantly increased which contributed to the huge third-order nonlinear behaviors. As Al2O3 increased, the χ(3) and n2 increased while the optical limiting threshold decreased. Glass A75 exhibited excellent optical linear, nonlinear, and emission properties which are promising for photonics device applications.