A quantitative characterization of micro-gravity and unit-gravity processed ZBLAN glass

Micro-gravity processing has been proven to suppress crystallization in ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN) glass. Crystallization suppression and characterization is the next step towards the development of low-loss mid-Infrared (IR) fiber optics. This study focuses on the characterization of micro-gravity versus unit-gravity processed ZBLAN glass. A unique quantitative crystallization characterization technique was employed on the samples that utilize a combination of Differential Interference Contrast (DIC) optical microscopy with on board microscope counting and measuring software techniques. To date, past researchers who have studied the crystallization suppression of ZBLAN glass in micro-gravity have only characterized their material through visual inspection of micrographs. This study makes use of optical micrographs while providing additional quantitative data that has been lacking from previous studies. This novel characterization technique provides additional insight into understanding the crystallization behavior of ZBLAN glass that can lead to the development of low-loss mid IR fiber optics. The results from this study show that the quantification data agrees with the micrographs, however, the new results show a more precise degree of crystallization suppression through quantified data, such as crystallite size and amount per sample.