Enhancement of upconversion luminescence due to the formation of nanocrystals in

Optically transparent Er3+-doped tellurite-based nanocrystallized glasses with the composition of 70TeO2-15Li2O-15Nb2O5-0.5Er2O3 (mol) have been prepared by a conventional melting quenching and the subsequent heat treatment processes. The sizes of grown nanocrystals in glass matrix appear to be 35-5