Patent ID: 9650285
Date: 2017-05-16
CPC Classifications: C03C

Claim:
1. A glass comprising, by mass %, the following components: 20 to 35% of SiO 50 to 70% of La 37 to 69% of La 0 to 3% of Gd 3 to 30% of Y 0% or more but less than 2% of Yb 2 to 15% of ZrO 2 to 6% of TiO 0 to 4% of ZnO, and 0 to 2% of WO wherein a mass ratio of the total content of La wherein a mass ratio of the SiO wherein a mass ratio of the Y wherein a mass ratio ZnO/Nb a refractive index nd is in a range of 1.800 to 1.830, and an Abbe's number vd is in a range of 45 to 48, wherein a relationship between the refractive index nd and the Abbe's number vd satisfies the equation: nd>2.585−0.017×vd.