New materials for fiber optics based on KBF4-BPO4-LiF and KBF4-BPO4 glasses are present. Transition of fluor-ion from BF4 groups to phosphorous were investigated. New glasses have refractive index lower than 1.430. With these glasses construction of fiber tip was offered. This new tip has a mechanical resistance 2 - 3 larger than polymer analogs, is efficient at LNT and may collect a set of 500 W laser without being destroyed. Corrosion degree of SiO2-glass on several fluor-containing melts was determined under some conditions. These melts appear corrosion activity as under as above the melt.
"New materials for commutation elements", Proc. SPIE 1792, Components for Fiber Optic Applications VII, (19 February 1993); doi: 10.1117/12.141198; https://doi.org/10.1117/12.141198