Up-conversion in nanostructured Yb 3+-Tm 3+ co-doped sol-gel derived SiO 2-LaF 3 transparent glass-ceramics

1. Méndez-Ramos, J.
2. Velázquez, J.J.
3. Yanes, A.C.
4. Del-Castillo, J.
5. Rodriguez, V.D.