Study of Optical Absorption and Fluorescence of Pr$^{\mathrm{3+}}$ Doped Lead Boro-Germanate Glasses

Lead boro-germanate glasses doped with Pr $^{\mathrm{3+\thinspace }}$ions [x PbO-10 GeO$_{\mathrm{2}}$(90-x) B$_{\mathrm{2}}$O$_{\mathrm{3}}$0.5 Pr$_{\mathrm{2}}$O$_{\mathrm{3}}$, x $=$ 20, 30, 40, 50, 60 mol {\%}] are prepared by the conventional melt quenching technique. The glasses are studied using optical absorption, refractive index, and fluorescence measurements. The refractive index is measured using the Brewster's angle method. Optical absorption is recorded by a Varian CARY 5G UV-VIS spectrometer. From the absorption spectra, oscillator strengths, intensity parameters and radiative transition probabilities are calculated. The Pr$^{\mathrm{3+}}$ fluorescence spectrum is obtained by exciting the glass sample at 445 nm wavelength and examining the light emitted by the excited atoms with a LEOI-101 modular multifunctional grating spectrometer. Stimulated emission cross section ($\sigma_{\mathrm{P}})$ is one of the most important optical parameters and large values of that can improve the efficiency of energy conversion process in a photovoltaic cell operation We obtained the stimulated emission cross section for Pr$^{\mathrm{3+}}$ fluorescing transitions using the optical absorption parameters and fluorescence parameters. $\sigma _{\mathrm{P}}$ values are found to be large for these glasses and it shows compositional dependence