Abstract: A component for the transmission of light of high energy density with a wavelength between 250 nm and 400 nm is made of synthetic, high-purity fused vitreous silica having a hydroxyl ion content in the range between 50 ppm and 1200 ppm and an under-stoichiometric content of oxygen for the achievement of a minimal transmission variation in the transmission of the light.

Abstract: The invention relates to lenses, prisms or other optical members which are subjected to high-power ultraviolet light having a wavelength of about 360 nm or less, or ionizing radiation, particularly optical members for use in laser exposure apparatus for lithography, and to blanks for such optical members. The homogeneity of the refractive index distribution and the resistance to optical deterioration when the optical members are exposed for a long period of time to short wavelength ultraviolet light from a laser beam are improved. The optical members are made of high-purity synthetic silica glass material containing at least about 50 wt. ppm of OH groups, and are doped with hydrogen.