Spectroscopic studies of neodymium-doped borate glasses and calculation of Judd-Ofelt parameters

Abstract

Borate glasses doped with Nd₂O₃ [H₃BO₃-Pb₃O₄-ZnO-X Nd₂O₃] have been prepared using the rapid cooling method. Glasses containing different concentrations of Nd₂O₃ doped were prepared in the temperature range of 1100 °C. The glassy nature of the synthesized samples is confirmed by the X-ray diffraction (XRD) pattern. Laser Raman spectra have been recorded using 532 nm and 785 nm laser excitation to study the vibrational nature of the glass structure. In the FT-IR studies, identify the functional group in the neodymium-doped borate glasses. The absorption spectra Tauc plot is used to calculate the optical band gap of the synthesized sample. The spectroscopic properties of the neodymium-doped ions were measured by the Judd-Ofelt theory. Furthermore, to study the synthesized glasses' spectroscopic properties, the absorption spectra are recorded in the range of 400 nm–900 nm. Moreover, the Judd-Ofelt parameter has been calculated for the synthesized sample, the calculated values of Ω_λ X 10⁻²⁰ cm² (λ = 2,4,6) are 2.78, 2.43, 2.57 for BNdBAG, 1.43, 0.97, 1.27 for CNdBAG and 1.48, 1.01, 1.31 for DNdBAG glasses. The spectroscopic quality factor is also calculated for all the synthesized samples. The Judd Ofelt parameter follows the trends Ω₂ > Ω₆ > Ω₄. Phonon lifetime is calculated for all the synthesized samples. Three near-IR emission bands were observed in the neodymium ions-doped borate glasses under the excitation of a 532 nm laser diode. The radiative transitions of ⁴F_3/2 → ⁴I_9/2, ⁴F_3/2 → ⁴I_11/2, and ⁴F_3/2 → ⁴I_13/2 are responsible for the three main emission bands that are produced by the lasing action of Nd³⁺-doped glass at approximately 902, 1021, and 1343 nm, respectively. The radiative lifetime (τ_R) and the decay radiative rate (W_R) are also calculated by using fluorescence spectra.