Optical glass, hot-molded article and method of manufacturing the same, optical element and method of manufacturing the same

Abstract

An optical glass includes P2O5, B2O3 and a rare earth oxide as essential components, and in a glass composition based on oxides, the P2O5 content is in the range of over 0 weight % and less than 0.79 weight %, the B2O3 content is in the range of 20-40 weight % and the total content of the rare earth oxide and an oxide selected from the group including of Ta2O5, WO3, TiO2, Nb2O5 and Bi2O3 is in the range of 35-70 weight %. Further, this optical glass has a refractive index (nd) in the range of 1.72-1.83, an Abbe number (υd) in the range of 45-55 and a glass transition temperature (Tg) of 640° C. or less.

Dependencies are inferred from the claim text.