| 摘要 |
PROBLEM TO BE SOLVED: To provide a silica glass that emits delayed fluorescence in response to irradiation with UV rays and that is used for a silica glass UV sensor using delayed fluorescence.SOLUTION: A synthetic silica glass is configured to have an OH group content of 1 ppm or less, a chlorine content of 30 ppm or less, a transmittance of 50% or less in the glass having 2 mm thickness at a wavelength of 190 nm, viscosity (Log&eegr;) of 12.0 poise or more at 1280°C, and oxygen deficiency, and to convert wavelengths, when irradiated with UV rays from a low-voltage mercury lamp at a wavelength of 254 nm, to emit delayed fluorescence in a visible light region from 400 to 650 nm with 0.01 sec or longer delay. A silica glass is configured to have a transmittance of 60% or less at a wavelength of 200 nm in the glass having 2 mm thickness, viscosity (Log&eegr;) of 12.3 poise or more at 1280°C, and a triplet excitation electron level and a singlet excitation electron level, and to convert wavelengths, when irradiated with UV rays, to emit delayed fluorescence in a visible light region with 1 sec or longer delay. |
