Thermal, Optical Properties and Structural Investigation of Tm3+ doped TeO2-ZnO-TiO2 Glass System İdris Kabalci, Neşe Öztürk Körpe, Tuğba Duran, Mustafa Özdemir, Turgay Tay and Gönül Özen Published online: 23 December 2010 DOI: 10.1051/iesc/2010mpcm03005