Broadband infrared luminescence of Ni~(2+)-doped silicate glass-ceramics containing lithium aluminate spinel nanocrystals

摘要

Transparent Ni~(2+)-doped SiO_2-Al_2O _3-Ga_2O_3-Li_2O (LGAS) glass-ceramics embedding lithium aluminate spinel nanocrystals was prepared. After heat treatment, LiAl_5O_8 crystallite was precipitated in the glasses, and its size was about 3 nm. It was confirmed from the absorption spectra that the ligand environment of Ni~(2+) ions changed from the trigonal bi-pyramid fivefold sites in the as-made glass to the octahedral sites in the glass-ceramics. Upon excitation at 980 nm, broadband infrared luminescence centered at around 1250 nm with full width at half maximum (FWHM) more than 250 nm was observed originating from the ~3T _2(~3F) → ~3A_2(~3F) transition of Ni~(2+) in octahedral sites. The broadband near-infrared (NIR) emission from Ni2+-doped glass-ceramics can be as host materials for broadband optical amplifier.