Performance and structure evolution of fluoindinate glass at high temperatures

Abstract

Fluoindinate glass (FIG) is considered an ideal material for fiber laser devices and mid-infrared bulk optics components owing to its ultra-low phonon energy and broad transparency window. However, the heat generated by devices fabricated with FIG during their operation limits its application. Therefore, there is an urgent need to study its high-temperature properties. In this study, the thermal properties, microstructure, crystal phase behaviors, and optical and luminescent properties of high-temperature FIG were comprehensively evaluated. We also attempted to reveal the changes in its structure at high temperatures using variable-temperature Raman spectroscopy. We first found that the stretching vibration intensity of nonbridging F(F nb ) decreases, and the bending vibration of FIG increases with an increase in temperature, indicating that high temperatures could lead to the fracture of bridge bonds between some [InF 6 ] 3− octahedrons. Certainly, this will lead to glass structural instability, which will further increase the tendency of FIG to undergo devitrification in high-temperature conditions. We believe that this work will provide a reference for the performance improvement and application of fluoride glass at high temperatures.

Study on corrosion process and mechanism of fluoride laser glass fiber

“…Under exposed environmental conditions, high-temperature treatment causes a significant enhancement of hydroxyl absorption in fluorinated glass, as evidenced by an enhanced absorption peak near 3 μm on the IR transmittance curve. [11] This is due to the increased hydroxyl content of the glass surface caused by the erosion of the glass surface by water in the atmosphere. In addition, in the chemical durability test, the fluoride glass lost significant weight after long-term water-bath erosion.…”