Synthetic quartz glass and process for producing it
AssigneeAsahi Glass Company, Limited
InventorsYoshiaki Ikuta, Shinya Kikugawa, Noriaki Shimodaira, Akio Masui, Shuhei Yoshizawa
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Abstract
A synthetic quartz glass for optical use, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which contains fluorine, which has a ratio of the scattering peak intensity of 2250 cm−1 (I2250) to the scattering peak intensity of 800 cm−1 (I800), i.e. I2250/I800, of at most 1×10−4 in the laser Raman spectrum, and which has an absorption coefficient of light of 245 nm of at most 2×10−3 cm−1.
Claims10
An optical element, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which comprises a synthetic quartz glass containing OH groups and fluorine and having a chlorine concentration of at most 25 ppm, wherein
- the synthetic quartz glass has
- a variation range of an OH group concentration of at most 15 ppm/105 mm, and
- a variation range of a fluorine concentration of at most 15 ppm/105 mm.
An optical element, to be used by irradiation with light within a range of from the ultraviolet region to the vacuum ultraviolet region, which comprises a synthetic quartz glass containing OH groups and fluorine and having a chlorine concentration of at most 25 ppm, wherein
- the OH groups and the fluorine are distributed in the synthetic quartz glass so that a concentration distribution of the OH groups offsets a concentration distribution of the fluorine;
- and
- the synthetic quartz glass has
- a variation range of an OH group concentration of at most 25 ppm/105 mm, and
- a variation range of a fluorine concentration of at most 25 ppm/105 mm.
Dependencies are inferred from the claim text.