OPTICAL GLASS

摘要

This invention provides a glass having a refractive index and a coefficient of thermal expansion close to those of quartz glass and having anti-devitrification properties good enough to avoid the development of defects such as devitrification on the surface of the glass upon wire drawing or re-hot molding, more specifically an optical glass for use in optical communication device, particularly an optical glass for a stub. The optical glass is characterized by comprising a borosilicate glass having a refractive index of 1.44 to 1.46, a coefficient of thermal expansion of 10 to 50 × 10<SUP>-7</SUP>/ºC, and a liquid phase viscosity of not less than 10<SUP>5.5</SUP> dPa·s.