Spectroscopic and luminescent properties of Nd3+-Al3+ co-doped silica glass prepared by spark plasma sintering

The Nd3+-Al3+ co-doped silica glass has drawn much attention due to the stability and efficient lasing emissions, while the high preparation temperature and residual hydroxyl groups restrict the further improvement of optical performance. In this work, transparent Nd3+-Al3+ co-doped glasses have been synthesized by spark plasma sintering at 980°C within 10 mins. Besides, adopting mesoporous powders as raw materials is beneficial to the homogeneous dispersion of ions in the glass. The transmittance, structure and luminescent properties were systematically investigated. The Judd-Ofelt intensity parameters were obtained to analyze the Al3+ co-doping effects. The PL intensity strongly depends on the ions concentration and the best value is obtained when the Nd3+ concentration is 1.0 mol% and ratio of Nd:Al is 1:7. In addition, the calculated emission cross section is 2.12, which is larger than the majority of previously reported values, suggesting that as-prepared silica glasses are candidates for laser host materials.