Size-induced crystal field parameter change and tunable infrared luminescence in Ni²⁺-doped high-gallium nanocrystals embedded glass ceramics

Transparent Ni2+-doped Li2O-Ga2O 3-SiO2 glass ceramics (GCs) were prepared and characterized. By controlling the size of the nanocrystals, the infrared luminescence is tunable. It could be ascribed to alteration of the crystal field strength Dq of octahedral Ni2+, which is due to the changes of the lattice parameters. The change in optical signals at telecommunication bands when the seed beam passes through the bulk sample with or without 980 nm excitation was also demonstrated for the first time. The coefficient of the change in optical signals at 1.3 μm is calculated as 0.26 cm-1. The changes in optical signal have shown similar wavelength dependence on the luminescence property.