Thermodynamic Properties and Optimized Fiber-Drawing Condition in Germanium Tellurite Glasses

Abstract

Thermodynamic properties of the heavy metal germanium tellurite (NZPGT) core and cladding glasses have been investigated. Coefficient of thermal expansion (CTE) and softening temperature (Ts) of the Er3+⁄Yb3+ codoped NZPGT core glasses were identified to be 1.89×10–5 °C–1 and 343 °C, respectively. Glass transition temperature (Tg), onset crystallization temperature (Tx), peak temperature of crystallization (Tc), temperature difference value (ΔT) and thermal stability parameter (H) of the core glasses were solved to be 290 °C, 412 °C, 470 °C, 122 °C and 0.42, respectively, and the corresponding vaules of cladding glasses were derived to be 290 °C, 391 °C, 400 °C, 101 °C and 0.35. The investigation results indicate optical fiber drawing of Er3+⁄Yb3+ codoped medium-low phonon energy NZPGT glasses can be achieved in the temperature range 345—380 °C, which provides a valuable temperature reference for further high-quality optical fibers drawing in developing optical devices.