Luminescence features of Dy3+-doped B2O3 and B2O3-P2O5 hosts for optical devices: the linear and non-linear optical studies

The glass with various concentrations of trivalent rare earth Dy3+ in borate and boro-phosphate host structures, along with alkali and transition metals, was synthesized by the melt-quenching technique. An FT-IR and FT-Raman spectrum reveal the structural features by tracing out the various molecular vibrations of borate and phosphate units. UV–Vis-NIR spectral analysis was used to investigate the effect of RE concentration on linear (Eg, ∆E, n1, and χ(1)) and non-linear (χ(3), n2) optical characteristics. The metal–oxygen bond character is explored in relation to the impact of alkali cations on the χ(3) of alkali borate and boro-phosphate host glasses. Photoluminescence emission spectra obtained in the optical zone show two intense band emissions traced at 482 and 574 nm, which correspond to 4F9/2 → 6H15/2 (electric-dipole transition) and 4F9/2 → 6H13/2 (magnetic-dipole transition), respectively, and one weak emission at 674 nm, which corresponds to 4F9/2 → 6H11/2. The fluorescence decay time was measured and fitted with the characteristics of a non-exponential decay profile. The estimated color coordinates are in the white region of the CIE 1931 chromaticity curve and are quite close to the conventional white illuminant (0.330, 0.330). In addition, the computed yellow-to-blue (Y/B) ratio and correlated color temperature of the prepared photonic glasses could allow tweaking white light emission via varying concentrations and host environments, which might be advantageous for various optical-based device fabrications.