Nd-doped BO-SiO-AlF-NaF-CaF glass ceramics for 1.06 μm emission.

Trivalent neodymium (Nd) doped transparent oxyfluoroborosilicate glass and glass ceramics (GCs) comprising CaF nanoparticles (NPs) were fabricated via melt quench route followed by two step heat treatment process. The X-ray diffraction and scanning electron microscopic studies confirm the presence of CaF NPs. The GC environment for efficient luminescence was obtained at a heat treatment of 450 °C/1 h. The wavelength of pumping laser source was optimized as 808 nm by studying the luminescence properties at different excitations. The Nd ions exhibit their characteristic emission transitions with peak maxima at around 0.89 μm (F → I), 1.06 μm (F → I) and 1.32 μm (F → I). The Nd concentration was also optimized as 1.0 mol% for strong emission up on 808 nm pumping. Various spectroscopic, radiative and laser characteristic parameters were determined using Judd-Ofelt theory. The luminescence decay of F state was studied controlling the excitation and emission wavelengths at 808 and 1060 nm, respectively. The reasons for quenching in luminescence were discussed with suitable illustrations. The experimentally observed results confirm that the GC sample obtained at 450 °C/1 h heat treatment was highly appropriate to design 1.06 μm fiber lasers and optical amplifiers.