Erbium (Er3+)-doped tungstate-tellurite (TWZ) glasses were developed for broadband luminescence, obtaining a full width at half maximum (FWHM) of 106 nm in the emission range of 1.45–1.65 μm. Higher refractive indices (2.1504–2.1697) and very low Abbe number (16.0–16.8) were determined by variable angle spectroscopic ellipsometry. Near-infrared (NIR) and Stokes emission profiles as well as bandwidths were tailored through Er3+ ion concentration upon 488 and 980 nm excitation. The effect of radiation trapping was investigated by varying the optical path length of the sample. The broadband NIR and visible luminescence was due to the 4 I 13/2→4 I 15/2 and (2 H 11/2, 4 S 3/2) → 4 I 15/2 transitions, respectively, of Er3+ ions. Lifetime of the4 I 13/2 level was found to decrease (3.41–0.85 ms) with increases in Er3+ ion concentration after an initial increase (3.17–3.41 ms). Photoluminescence quantum yield (PLQY) of the 4 I 13/2→4 I 15/2 transition was studied by exciting at 980 nm laser, revealing an optimal concentration of 0.5 mol% Er2O3. These results suggest that the Er3+:TWZ glasses may find the applications in broadband tunable lasers as well as in devices for integrated optics owing to their high refractive index and low dispersion.
Krishnaiah, K. V., Venkataiah, G., Marques-hueso, J., Dharmaiah, P., Jayasankar, C. K., & Richards, B. S. (2015). Broadband Near-Infrared Luminescence and Visible Upconversion of Er3+-Doped Tungstate-Tellurite Glasses. Science of Advanced Materials, 7(2), 345-353. https://doi.org/10.1166/sam.2015.2027