Abstract: A silica glass article, such as a lens in a stepper/scanner system, having saturated induced absorption at wavelengths of less than about 250 nm. Saturated induced absorption is achieved by first removing Si—O defects in the silica glass by forming silicon hydride (SiH) at such defects, and loading the silica glass with hydrogen to react with E? centers formed by photolysis of SiH in the silica glass article. The silicon hydride is formed by loading the silica glass with molecular hydrogen at temperatures of at least 475° C. After formation of SiH, the silica glass is loaded with additional molecular hydrogen at temperatures of less than 475° C.

Abstract: A method of controlling blister formation in a glass melt flowing through a system comprising one or more refractory metal vessels by developing a blister index and determining the critical blister index value. The critical value of the blister index may be used to control the principal variables responsible for blister formation, including the water content of the melt, the concentration of reduced multivalent oxide compounds in the melt, and the hydrogen partial pressure of an atmosphere in contact with the outside surface of the refractory metal vessel. Also disclosed is a minimum partial pressure of hydrogen necessary to produce an essentially blister-free glass article in a glass essentially free of arsenic and antimony.

Abstract: A method of controlling blister formation in a glass melt flowing through a system comprising one or more refractory metal vessels by developing a blister index and determining the critical blister index value. The critical value of the blister index may be used to control the principal variables responsible for blister formation, including the water content of the melt, the concentration of reduced multivalent oxide compounds in the melt, and the hydrogen partial pressure of an atmosphere in contact with the outside surface of the refractory metal vessel. Also disclosed is a minimum partial pressure of hydrogen necessary to produce an essentially blister-free glass article in a glass essentially free of arsenic and antimony.

Abstract: Disclosed in the application are a synthetic silica glass having low fluence-dependent transmission, particularly at about 193 nm, and a process for making the same. The glass may desirably exhibit a low level of fluorescence at 290 and 390 nm when activated at about 248 nm. The glass may desirably exhibit low level of LIWFD, [SiH*] and/or [ODC].

Abstract: A silica glass article, such as a lens in a stepper/scanner system, having saturated induced absorption at wavelengths of less than about 250 nm. Saturated induced absorption is achieved by first removing Si—O defects in the silica glass by forming silicon hydride (SiH) at such defects, and loading the silica glass with hydrogen to react with E? centers formed by photolysis of SiH in the silica glass article. The silicon hydride is formed by loading the silica glass with molecular hydrogen at temperatures of at least 475° C. After formation of SiH, the silica glass is loaded with additional molecular hydrogen at temperatures of less than 475° C.

Abstract: Feed materials are melted in a furnace to form a glass melt at a first temperature T1, the glass melt containing at least one fining agent. The glass melt is cooled to a second temperature T2 less than T1, and an oxygen-containing gas is bubbled through the cooled melt. The glass melt is then re-heated to a third temperature T3 equal to or greater than the first temperature T1.

Abstract: Disclosed is a synthetic silica glass optical material having high resistance to optical damage by ultraviolet radiation in the ultraviolet wavelength range, particularly in the wavelength less than about 250 nm and particularly, exhibiting a low laser induced wavefront distortion; specifically a laser induced wavefront distortion, measured at 633 nm, of between about ?1.0 and 1.0 nm/cm when subjected to 10 billion pulses of a laser operating at approximately 193 nm and at a fluence of approximately 70 ?J/cm2. The synthetic silica glass optical material of the present invention comprises OH concentration levels of less than about 600 ppm, preferably less than 200 ppm, and H2 concentration levels less than about 5.0×1017 molecules/cm3? and preferably less than about 2.0×1017 molecules/cm3.

Abstract: Disclosed is a synthetic silica glass optical material having high resistance to optical damage by ultraviolet radiation in the ultraviolet wavelength range, particularly in the wavelength less than about 250 nm and particularly, exhibiting a low laser induced wavefront distortion; specifically a laser induced wavefront distortion, measured at 633 nm, of between about ?1.0 and 1.0 nm/cm when subjected to 10 billion pulses of a laser operating at approximately 193 nm and at a fluence of approximately 70 ?J/cm2. The synthetic silica glass optical material of the present invention comprises OH concentration levels of less than about 600 ppm, preferably less than 200 ppm, and H2 concentration levels less than about 5.0×1017 molecules/cm3,and preferably less than about 2.0×1017 molecules/cm3.

Abstract: Disclosed are high purity synthetic silica material having an internal transmission at 193 nm of at least 99.65%/cm and method of preparing such material. The material is also featured by a high compositional homogeneity in a plane transverse to the intended optical axis. The soot-to-glass process for making the material includes a step of consolidating the soot preform in the presence of H2O and/or O2.