| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultraviolet resistant glass material having high ultraviolet resistance even when irradiated with high output laser such as excimer laser in an ultraviolet region and having excellent optical properties of transparency, transmittance, double refraction and refractive index homogeneity. SOLUTION: The concentration of an Si-F bond contained in the glass material is 100-10,000 wt.ppm, the concentration of dissolved nitrogen is 100-10,000 wt.ppm, the concentration of OH group contained in the glass is <10 wt.ppm and the concentration of metallic impurities comprising a group containing typical metals and transition metal elements is <50 ppb. COPYRIGHT: (C)2005,JPO&NCIPI |
