Effect of Al on photoluminescence properties of Nd³⁺ in silicate glass prepared by in-situ sol-gel method

This article discusses our investigations into the structural and spectroscopic properties of Nd³⁺ co-doped alumino-silicate glass prepared by an in-situ sol-gel method. Structural characterization was carried out using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The XRD analysis reveals that the material is still amorphous even after being heated to 900 °C. FTIR analysis was used to identify the functional groups of the produced sol-gel silicate glass. The optical absorption spectra from the ground state ⁴I_9/2 show seven peaks in the UV-VIS and NIR regions. The optical absorption spectrum of Nd³⁺ co-doped alumino-silicate glass-ceramic was used to determine the Judd-Ofelt (JO) intensity parameters (Ω₂, Ω₄ and Ω₆). The photoluminescence (PL) spectrum was recorded with a 2W diode laser source of 808 nm excitations. From the larger stimulated emission cross-section (3.80 x 10⁻²⁰ cm²) of the ⁴F_3/2 → ⁴I_11/2 transition, it is concluded that the SiNdAl glasses could be highly useful for the development of solid state laser materials. From the observed refractive indices at three different wavelengths, non-linear parameters for the glass, such as the Abbe number (υ_Ab) and non-linear refractive index (n₂), are derived.