Mass

摘要

PROBLEM TO BE SOLVED: To provide a glass composition which has both of low temperature coefficient of the refractive index and excellent light transmittance, and is suitable for use in an environment of large temperature change.;SOLUTION: The optical glass is one that has a temperature coefficient (20-40°C) of the relative refractive index (546.07 nm) of 10.0×10^-6(°C^-1) or smaller, or one that has a temperature coefficient (20-40°C) of the relative refractive index (546.07 nm) of 4.6×10^-6(°C^-1) or smaller, or one that has an internal transmittance (τ10 mm) at 400 nm of 80% or greater, in a glass composition which includes SiO₂, B₂O₃ and La₂O₃.;COPYRIGHT: (C)2007,JPO&INPIT