OPTICAL GLASS, OPTICAL ELEMENT, AND PREFORM FOR PRECISION PRESS MOLDING

摘要

Disclosed is optical glass which has a low Abbe number (?d) even though the refractive index (nd) thereof is within a desired range, and which is highly transparent to visible light. Also disclosed are an optical element and a preform for precision press molding. The optical glass contains, in mass% relative to the total mass of the glass in terms of oxides, 5.0-40.0% of a P2O5 component and 10.0%-60.0% of an Nb2O5 component. The optical element and the preform for precision press molding are composed of the optical glass.