Patent ID: 8329602
Filing Date: 2012-12-11
Classification: C03C

Abstract:
1. An optical glass for a light guide, an image guide or a glass lens for an exposure device for semiconductors comprising each of SiO 2 , B 2 O 3 , BaO, and Ta 2 O 5 , La Nb wherein the optical glass is free of a lead compound, an arsenic compound, BaCl the optical glass having the ratio of Ta having internal transmittance of 0.9900 or over at a wavelength within a range from 400 nm to 450 nm and internal transmittance of 0.9980 or over at a wavelength within a range from 600 nm to 700 nm as measured respectively in accordance with the Japan Optical Glass Industry Standard JOGIS17 wherein the optical glass is a core material of an optical fiber.