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 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: 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: The disclosure is directed to a photoelastic method for measuring the absolute zero crossover temperature Tzc of a sample of materials (transparent glass, glass-ceramic or ceramic) directly, without requiring calibration against a primary technique. The method involves subjecting the sample to a temperature gradient that generates a stress distribution pattern within the sample. When some portion of the sample is at a temperature equal to the Tzc of the material, the pattern adopts an easily identifiable shape whose measurement allows the calculation of Tzc. Silica-titania glass, which has a low thermal expansion, is used as an exemplary material.

Abstract: Disclosed embodiments include an apparatus for water sampling and analysis, the apparatus comprising: (a) a device for water sampling at a plurality of depths comprising a hosepipe and a plurality of internal independent pipes with a plurality of sampling inlets at a plurality of water depths, and (b) a pumping system to pump a sample of water collected using the device for water sampling at a plurality of depths to an isolated module for analysis. According to one embodiment, the apparatus is an autonomous multi-parametric buoy with capabilities for multi-depth water sampling, self-maintenance, monitoring, data collection, transmission, and analysis.

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: 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: 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: 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: 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: The disclosure is directed to a photoelastic method for measuring the absolute Tzc of a sample of materials (transparent glass, glass-ceramic or ceramic) directly, without requiring calibration against a primary technique. The method involves subjecting the sample to a temperature gradient that generates a stress distribution pattern within the sample. When some portion of the sample is at a temperature equal to the Tzc of the material, the pattern adopts an easily identifiable shape whose measurement allows the calculation of Tzc. Silica-titania glass, which has a low thermal expansion, is used as an exemplary material.

Abstract: Disclosed embodiments include an apparatus for water sampling and analysis, the apparatus comprising: (a) a device for water sampling at a plurality of depths comprising a hosepipe and a plurality of internal independent pipes with a plurality of sampling inlets at a plurality of water depths, and (b) a pumping system to pump a sample of water collected using the device for water sampling at a plurality of depths to an isolated module for analysis. According to one embodiment, the apparatus is an autonomous multi-parametric buoy with capabilities for multi-depth water sampling, self-maintenance, monitoring, data collection, transmission, and analysis.

Abstract: The invention represents an improved method of measuring trenches on semiconductor wafers with optical spectroscopy. According to the described method, it is possible to characterize not only depth but also shape of the trench. The advancement is achieved by improved Effective Medium Approximation-based modeling of the optical response of trench structures.

Abstract: A multi-leaflet valve adapted to serve as a prosthesis for diseased native valve of a mammal is incorporated in self-expandable or inflatable endovascular stents or stents to form a combination which is introduced on a catheter with a guide wire into the circulatory system of the mammal to replace the diseased native valve. Once the combination is at the desired location the stent is caused to expand and affix itself to the patient's vessel wall. The prosthetic valve has the shape of a truncated cone that has an inflow and an outflow orifice with leaflets forming the outflow orifice and forming a plurality of commissures. A first flexible circular support is affixed in a substantially circular fashion around the truncated cone in proximity of the inflow orifice, and a second flexible circular support is affixed at the location of the commissures to form a circle around the truncated cone in proximity of the outflow orifice.

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: The invention represents an improved method of measuring trenches on semiconductor wafers with optical spectroscopy. According to the described method, it is possible to characterize not only depth but also shape of the trench. The advancement is achieved by improved Effective Medium Approximation-based modeling of the optical response of trench structures.

Abstract: Methods and systems are provided for writing a magnetic servo track. In one example, a system includes a head assembly having first and second write elements, and a controller. The controller operable to receive a position signal associated with a position of the magnetic storage medium and energize the first write element to write a first magnetic servo pattern (e.g., repeating servo frames including a tone field). The controller is further operable to energize the second write element to write a second magnetic servo pattern (e.g., a mid-frame mark) at least partially overlapping the first pattern, wherein the relative position of the second pattern is adjusted in response to the position signal. The second pattern may be displaced relative to the first pattern in response to a lateral displacement of the magnetic storage medium to maintain a desired center line condition of the servo track.

Abstract: Structures are characterized by exposing a sample to optical radiation, measuring a spectrum associated with the exposure, detecting at least one characteristic parameter in the measured spectrum, and computing at least one structural parameter based on the at least one characteristic parameter.

Abstract: A valve repair system, preferably including an annuloplasty prosthesis and a holder for the prosthesis. The holder includes a first component having a central opening, a circumferential surface and an outwardly extending member. The annuloplasty prosthesis is located adjacent to the circumferential surface, above the outwardly extending member. The holder further includes a second component movable upwardly relative to the first holder component and includes a rigid penetrating member extending downward from the second component into the prosthesis, holding it adjacent the circumferential surface. The holder also includes a suturing guide for assisting a physician in valve repair surgery, which may be a cuttable suture extending across the central opening along a path approximating a desired line of leaflet coaption. The cuttable suture may additionally secure the first and second components to one another.