Effect of silica-alumina co-introduction on structure as well as physical and spectroscopic properties of Nd3+-doped potassium phosphate glass

Abstract

The effect of silica-alumina co-introduction on physical and spectroscopic properties of Nd3+-doped potassium phosphate glass was investigated. The Raman and X-ray photoelectron spectroscopy (XPS), physical parameters as well as spectroscopic characteristics were determined and analyzed in detail. Q2 units gradually increase while Q1 units have the opposite trend with the increase of SiO2/Al2O3 ratios. Meanwhile the total number of [AlO6] octahedrons and [AlO4] tetrahedrons continue to decrease with [AlO6]/ [AlO6]+ [AlO4] ratio keeping rise. As a result, the increase of more symmetrical bridge oxygen bonds and more ionic Si-O bonds lead to more centrosymmetric and stronger ionicity of Nd3+ ion coordination environment. The physical and spectroscopic properties of glasses benefit from silica-alumina co-introduction. When SiO2/Al2O3 ratio was 1.8, the glass showed a high emission cross-section of 3.05 × 10−20 cm2, a high optical gain parameter of 10.8 × 10−24 cm2s, together with wider gain bandwidth parameter of 7.61 × 10−26 cm3.