Abstract:
A method for producing a synthetic silica glass for use with vacuum ultraviolet light comprises the steps of: (a) producing a soot preform; (b) heating the soot preform in an atmosphere containing fluorine to obtain a fluorine-doped soot preform; (c) consolidating the fluorine-doped soot preform to obtain a fluorine-doped synthetic silica glass; and (d) heating the fluorine-doped synthetic silica glass in an atmosphere containing hydrogen gas to obtain a synthetic silica glass doped with fluorine and hydrogen molecules. A synthetic silica glass having both a high transmittance and high ultraviolet light resistance with respect to light in the vacuum ultraviolet wavelength range can be produced.
Abstract:
Optical glass is produced by heating a porous gel to a high temperature to partly sinter it, heating it in a chlorine-containing atmosphere to subject it to hydroxyl group removal treatment, and then further heating it to sinter it. The optical glass produced by this process does not rise in bubbles even when heated.
Abstract:
The present invention relates to a process for the continuous manufacture of vitreous synthetic silica doped with fluorine. This process consists of decomposing a silicon compound free of hydrogen in the flame of an inductive plasma burner, thereby forming silica upon reacting with the oxygen contained in the burner feed gas. A gaseous inorganic fluorine compound free of hydrogen, is sent into the flame preferably from outside the burner. Said fluorine compound simultaneously with the silicon compound decomposes whereby fluorine is introduced into the silica, lowering its index of refraction. The doped silica is then deposited on a heat-stable support in the form of a vitreous mass. The doped synthetic silica is particularly useful for making preforms for optical transmission fibers.
Abstract:
A doped silica-titania glass article is provided that includes a glass article having a glass composition comprising (i) a silica-titania base glass, (ii) a fluorine dopant, and (iii) a second dopant. The fluorine dopant has a concentration of fluorine of up to 5 wt. % and the second dopant comprises one or more oxides selected from the group consisting of Al, Nb, Ta, B, Na, K, Mg, Ca and Li oxides at a total oxide concentration from 50 ppm to 6 wt.%. Further, the glass article has an expansivity slope of less than 0.5 ppb/K2 at 20⃘C. The second dopant can be optional. The composition of the glass article may also contain an OH concentration of less than 100 ppm.
Abstract:
The invention relates to an optical component made of synthetic quartz glass for use in an ArF excimer laser lithography process with an applied wavelength of 193 nm, comprising a glass structure substantially free of oxygen defect sites, a hydrogen content ranging from 0.1 x 1016 molecules/cm3 to 1.0 x 1018 molecules/cm3, an SiH group content of less than 2 x 1017 molecules/cm3, and a hydroxyl group content ranging from 0.1 to 100 wt. ppm, said glass structure having a fictive temperature of less than 1070 °C. The aim of the invention is to allow a reliable prediction of the compacting behavior when using UV laser radiation with the applied wavelength on the basis of a measurement of the compacting behavior using a measured wavelength of 633 nm. This is achieved by an optical component design in which the component undergoes a laser-induced change in the refractive index in response to irradiation by means of a radiation with a wavelength of 193 nm using 5x109 pulses with a pulse width of 125 ns and a respective energy density of 500 µJ/cm2 at a pulse repetition frequency of 2000 Hz, said change totaling a first measured value M193nm when measured using the applied wavelength of 193 nm and totaling a second measured value M633nm when measured using a measured wavelength of 633 nm, wherein M193nm/M633nm