| 摘要 |
PROBLEM TO BE SOLVED: To provide, in a phosphate type glass, an optical glass that has a high refractive index and excellent transmittance.SOLUTION: The optical glass is provided which is a phosphate based glass and contains at least any one of oxides selected from TiO, NbO, WOand BiO, and in which the total content (HR) of the TiO, NbO, WOand BiOis 35 mol% or more, the noble metal content is less than 2.0 ppm, and the value of βOH represented by the formula (1) below is 0.1 mmor more. βOH=-[ln(B/A)]/t...(1).SELECTED DRAWING: None |
