| 摘要 |
The present invention relates to an optical member including a TiO2-containing silica glass having: a TiO2 concentration of from 3 to 10% by mass; a Ti3+ concentration of 100 wt ppm or less; a thermal expansion coefficient at from 0 to 100° C., CTE0-100, of 0±150 ppb/° C.; and an internal transmittance in the wavelength range of 400 to 700 nm per a thickness of 1 mm, T400-700, of 80% or more, in which the optical member has a ratio of variation of Ti3+ concentration to an average value of the Ti3+ concentration,ΔTi3+/Ti3+, on an optical use surface, is 0.2 or less. |
