Investigation of phase separation as a source of optical losses in IR glasses for fiber optics

Extremely tough requirements for the optical transparency of IR glasses for fiber optics determine the specifics of the study of phase separation in such materials. Theoretical approaches and experimental techniques of such research are proposed. The permissible contents of phase inclusions in IR glasses for active and passive fiber optics are estimated. The priority field of their control is identified and highly sensitive methods for its implementation are selected. Their effectiveness in choosing the most resistant to crystallization and liquation glasses for fiber optics is demonstrated by the example of GeSx (1.3 ≤ x ≤ 1.5) glasses. The selection criterion is the scattering losses caused by phase separation. For the first time, micro-liquation has been revealed in the studied compositions. Based on data on the sizes, contents, and refractive indices of phase inclusions, scattering losses in glasses obtained under various quenching conditions are estimated. The most promising glass compositions for fiber applications are established.