Abstract: A fused silica glass and a fused silica article having a combined concentration of at least one of OH and OD of up to about 50 ppm. The fused silica glass is formed by drying a fused silica soot blank or preform in an inert atmosphere containing a drying agent, followed by removal of residual drying agent from the dried soot blank by heating the dried soot blank in an atmosphere comprising an inert gas and of oxygen.

Abstract: This disclosure is directed to tailoring and improving the expansivity of low thermal expansion silica-titania glass through changes in the [OH] content and fictive temperature of the glasses. The [OH] concentration in the glass can be in the range of 600-2500 ppm. The fictive temperature, TF is less than 900° C.

Abstract: In one embodiment the present disclosure is directed to a silica-titania glass with an internal transmission of >90%/cm at wavelengths from 340 nm to 840 nm. In another embodiment the internal transmission is >93%/cm at wavelengths from 340 nm to 840 nm. In a further embodiment the internal transmission is >95%/cm at wavelengths from 340 nm to 840 nm. In another embodiment the disclosure is directed to a silica-titania glass with an overall transmission through an optic made of the glass is >84% at wavelengths from 340 nm to 840 nm. In another embodiment overall transmission through an optic made of the glass is >86% at wavelengths from 340 nm to 840 nm. In a further embodiment the overall transmission through an optic made of the glass is >88% at wavelengths from 330 nm to 840 nm. In a further embodiment the silica-titania glass has a Ti+3 concentration level [Ti3+] less than 3 ppm by weight.

Abstract: Disclosed are methods for hydrogen loading silica glass and silica glass comprising loaded H2. The methods can lead to H2 gradient in the glass material. Alternatively, the method may involve the use of varying H2 partial pressure of H2 in the atmosphere. Both can result in expedited hydrogen loading process.

Abstract: A low expansion glass substrate includes titania and silica and has a thermal expansivity with an average gradient less than 1 ppb/° C./° C. in a temperature range of 19° C. to 25° C.

Abstract: A method of making a silica glass having a uniform fictive temperature. The glass article is heated at a target fictive temperature, or heated or cooled at a rate that is less than the rate of change of the fictive temperature, for a time that is sufficient to allow the fictive temperature of the glass to come within 3° C. of the target fictive temperature. The silica glass is then cooled from the target fictive temperature to a temperature below the strain point of the glass at a cooling rate that is greater than the relaxation rate of the glass at the target fictive temperature. The silica glass has a fictive temperature that varies by less than 3° C. after the annealing step. A silica glass made by the method is also described.

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: The disclosure describes a method by which the Tzc of a silica-titania glass article, for example, a EUVL mirror substrate, can be tuned to within a specification range by means of a selected final anneal that shifts Tzc of the article or substrate to the desired Tzc value. In addition, since different mirrors in a set can be specified at different values of Tzc, this process can be on used glass samples or pieces from a single glass boule to make parts with different Tzc values, thus reducing the number of separate boules required to fill an order.

Abstract: A low thermal expansion glass includes a base glass material having a front surface, a back surface, and a thickness and a glass coating material applied on at least the front surface of the base glass material. The base glass material consists essentially 10 wt % to 20 wt % titania and 80 wt % to 90 wt % silica. The glass coating material also consists essentially of titania and silica, but the total amount of titania in the glass coating material is lower than the total amount of titania in the base glass material. A silica-titania glass element suitable for extreme ultraviolet lithography applications consists of 12 wt % to 20 wt % titania and 80 wt % to 88 wt % silica and has a coefficient of thermal expansion of essentially 0 ?L/L in a temperature range of ?20° C. to +100° C.

Abstract: A fused silica glass article having a low absolute refractive index and low concentrations of hydroxyl groups, halogens, and metal having a low absolute refractive index. The glass article contains less than about 10 ppm protium-containing and deuterium-containing hydroxyl groups by weight and less than about 20 ppm halogens by weight. The silica glass article also has an absolute refractive index (ARI) less than or equal to 1.560820. In one embodiment, the ARI of the fused silica article is achieved by lowering the fictive temperature of the fused silica. A method of lowering the fictive temperature is also described.

Abstract: A fused silica glass having a refractive index homogeneity of less or equal to about 5 ppm over an aperture area of at least about 50 cm2. The fused silica glass is also substantially free of halogens and has an adsorption edge of less than about 160 nm. The glass is dried by exposing a silica soot blank to carbon monoxide before consolidation, reducing the combined concentration of hydroxyl (i.e., OH, where H is protium (11H) and deuteroxyl (OD), where D is deuterium (12H)) of less than about 20 ppm by weight in one embodiment, less than about 5 ppm by weight in another embodiment, and less than about 1 ppm by weight in a third embodiment.

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: A low expansion glass substrate includes titania and silica and has a thermal expansivity with an average gradient less than 1 ppb/° C./° C. in a temperature range of 19° C. to 25° C.

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: A method of making a fused silica article that is loaded with hydrogen. A fused silica glass near net shape part is provided and is loaded with a molecular hydrogen in a range from about 0.1×1017 molecules/cm3 up to about 1×1019 molecules/cm3. The thinner shape of the near net shape part enables the shape to be loaded more quickly than previous methods. A fused silica article loaded with hydrogen using the method is also described.

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.

Abstract: A fused silica glass and a fused silica article having a combined concentration of at least one of OH and OD of up to about 50 ppm. The fused silica glass is formed by drying a fused silica soot blank or preform in an inert atmosphere containing a drying agent, followed by removal of residual drying agent from the dried soot blank by heating the dried soot blank in an atmosphere comprising an inert gas and of oxygen.

Abstract: A fused silica glass having a composition for use in bulk IR optical applications. The fused silica glass has a OH concentration of less than 5 ppm (parts per million) by weight and an absorbance of less than about 50 ppm/cm at a wavelength of about 1.3 ?m. A method of making the fused silica glass is also described.