Effect of B 2 O 3 Addition on the Thermal Stability of Barium Phosphate Glasses for Optical Fiber Devices

The effect of B 2 O 3 addition on the thermal stability of BaO–P 2 O 5 glasses is studied by differential thermal analysis (DTA), X‐ray diffraction (XRD) analysis, scanning electron microscopy, and micro‐Raman spectroscopy. The difference between glass‐transition and onset‐crystallization temperatures increases monotonically with increasing B 2 O 3 concentration. The DTA result reveals that no exothermic peak due to surface crystallization exists in the BaO–P 2 O 5 glass doped with 3 mol% B 2 O 3 . A single‐mode BaO–P 2 O 5 ‐B 2 O 3 glass fiber could be fabricated by a rod‐in‐tube technique. The modification of glass structure due to B 2 O 3 addition is qualitatively discussed.