Bright visible upconversion emission and thermally enhanced cooperative energy-transfer in Tb/sup 3+//Yb/sup 3+/-codoped tellurite glass

In this work, bright visible upconversion emission excited through cooperative energy-transfer and thermal effects in Tb/sup 3+//Yb/sup 3+/-codoped 60TeO/sub 2/-10GeO/sub 2/-10K/sub 2/O-10Li/sub 2/O-10Nb/sub 2/O/sub 5/glasses excited at 1.064 /spl mu/m is investigated. Bright upconversion luminescence around 485, 550, 590, 625 and 655 nm, identified as due to the /sup 5/D/sub 4//spl rarr//sup 7/F/sub J/(J= 6, 5, 4, 3, and 2) transitions of the terbium-ions, respectively, was generated.