Super broadband spectroscopic properties of Ni2+-doped silicate glass ceramics

A new Ni2+-doped Na2O-Al2O3-SiO2 - LaF3 (NASL) glass ceramics was prepared. X-ray diffraction (XRD) analysis confirmed the formation of LaF3 and La2O3 nano-crystals in the glass matrix, and their sizes were calculated as 23 and 37 nm respectively according to Scherrer formula. The absorption spectrum and fluorescence of Ni2+-doped NASL glass and glass ceramics were measured. It shows that the Ni2+-doped NASL glass ceramics has a broad fluorescence spectrum centering at 1185 nm with full width at half maximum of about 300 nm. The product of the lifetime and the stimulated emission cross section is 4.2 × 10-24cm2 · s. It is analyzed that the observed super broadband fluorescence spectrum of the Ni2+-doped NASL glass ceramics could be attributed to the 3T2 (3F) → 3A2 (3F) transition of Ni2+ that occupy high-field states in nano-crystals. Therefore, the Ni2+-doped NASL glass ceramics can be used as potential gain medium material for super broadband optical amplifiers.