瞬态光学研究室知识库

The photoluminescence and decay properties of Yb3+ /Ce3+ co-doped aluminosilicate glasses were investigated under ultraviolet irradiation. A strong excitation band was ascribed to 4f -> 5d transitions of Ce3+ ions. A broad ultraviolet-visible emission band belonged to 5d -> 4f transitions of Ce3+ ions and oxygen-deficient centers (ODCs) in the host matrix, and the visible-near infrared emission band was attributed to non-bridging oxygen hole centers. Comparative tests of the core composition were performed. The results showed Yb2O3 and the ODCs played a crucial role on ultraviolet-visible emission band. ODCs rather than Ce3+ ions were responsible for the 1-35 mu s lifetime decay of the ultraviolet-visible emission, but had no contribution to the longer decay lifetimes (77.58 Ns) for Ce-free Yb3+-doped glasses. A complex schematic energy-level diagram including the electron transfer mechanism such as Ce3+-Yb3+ -> Ce4+-Yb2+, the cooperative up- and down-conversion processes was proposed to describe different luminescence mechanisms UV-expose.