OPTICAL GLASS, OPTICAL ELEMENT, OPTICAL INSTRUMENT AND MANUFACTURING METHOD OF OPTICAL GLASS

摘要

PROBLEM TO BE SOLVED: To provide an optical glass, an optical element and an optical instrument.;SOLUTION: Optical glass includes, as a cation, a rare earth ion, a W ion, a Nb ion, a Ti ion and a Ga ion, as essential components, and a B ion as an optional component. An optical element such as a lens is obtained by molding the optical glass. An optical instrument includes the optical element, and a manufacturing method is for the optical glass. The transparent optical glass can be obtained with a large ΔTx (the ΔTx here having a glass transition point (Tg)-crystallization initiation temperature (Tx)), being one of indexes of devitrification resistance, while excellent in devitrification resistance, with high dispersion (Abbe number νd being 22-29) and low θgF(0.60-0.63).;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2018,JPO&INPIT