Optical and radiative properties of Nd3+-doped lead tellurite borate glasses

Glass samples of composition (in mol%) 20PbO-20TeO(2)-(60 - x)B2O3-xNd(2)O(3) (x = 0, 1, 2, 3, 4) were prepared by melt quenching. The glassy nature of as-quenched samples was established via differential scanning calorimetry. The amorphous nature of the glasses was confirmed via powder X-ray diffraction measurements. Judd-Ofelt (JO) analysis based on UV-visible absorption spectra was performed to determine JO parameters Omega(lambda) (lambda = 2, 4, 6). The observed trend is Omega(2) > Omega(6) > Omega(4). The large value of Omega(2) indicates the presence of covalent bonding between the Nd3+ ions and the surrounding ligands. Radiative properties, such as radiative transition probabilities, branching ratios, and radiative lifetimes are estimated. The glass samples have relatively high branching ratio, and their emission (A(em)) to excited state absorption (A(ESA)) intensity ratio is higher than one for the F-4(3/2) -> I-4(11/2) transition, indicating that the prepared glasses may have potential laser applications.