Abstract:
Fused silica members having high internal transmission and low birefringence are disclosed. Methods of making such fused silica members are also disclosed. According to the present invention, fused silica members having an internal transmission equal to or greater than 99.65%/cm at 193 nm and having an absolute maximum birefringence along the use axis of less than or equal to 0.75 nm/cm are provided.
Abstract:
A core glass for making a preform for an optical fiber particularly useful for the transmission of ultraviolet radiation and methods for making the core glass are disclosed. The core glass is obtained by the flame hydrolysis of a silicon compound, deposition of finely granular SiO2 on a substrate with direct vitrification and formation of a synthetic quartz glass. The quartz glass has a hydrogen content of less than 1null1018 molecules/cm3.
Abstract:
A method is provided for manufacturing a synthetic silica glass. The method includes the steps of maintaining a silica glass member, which is formed using a flame hydrolysis method and having an OH group concentration of about 500 ppm to about 1300 ppm, at a predetermined holding temperature for a predetermined period of time so as to substantially relax the structure of the silica glass member. The method further includes the step of subsequently cooling the silica glass member to a first predetermined temperature at a cooling rate of about 10 K/hour or less, and thereafter, cooling the silica glass member to a second predetermined temperature at a cooling rate of about 1 K/hour or less. The method further includes the step of further cooling the silica glass member to a third predetermined temperature at a cooling rate of about 10 K/hour or less.
Abstract:
There is disclosed second-order nonlinear glass material wherein a part having second-order nonlinearity contain Ge, H and OH and second-order nonlinear optical constant d of 1 pm/V or more, and a method for producing second-order nonliner glass material comprising treating a porous class material containing Ge with hydrohen, sintering it and subjecting it to a ultraviolet poling treatment. There can be provided second-order nonlinger glass material having second-order nonlinearity which is a sufficiently high and has a sufficiently long lifetime for a practical purpose, in use of the glass material for optical elements or the like.
Abstract:
A method is provided for manufacturing a silica glass that is substantially free of chlorine. The method includes the step of separately expelling a silicon tetrafluoride gas, a combustion gas, and a combustible gas from a burner made of silica glass, the flow velocity of the silicon tetrafluoride gas being within the range of about 9 slm/cm2 to about 20 slm/cm2. The method further includes the steps of producing minute silica glass particles by reacting the silicon tetrafluoride gas with water produced by a reaction of the combustion gas with the combustible gas, depositing the minute silica glass particles on a target, and producing the silica glass by fusing and vitrifying the minute silica glass particles deposited on the target.
Abstract:
High purity direct deposit vitrified silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive direct deposit vitrified silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a dry direct deposit vitrified silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive direct deposit vitrified silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1null1017 molecules/cm3 of molecular hydrogen and low chlorine levels.
Abstract translation:公开了适用于在190nm以下的VUV波长区域中用于光刻应用的光掩模基板的高纯度直接沉积玻璃化硅氧氟化物玻璃。 本发明的直接沉积玻璃化硅氧氟化物玻璃在157nm波长附近是透射的,使其特别适用于157nm波长区域的光掩模衬底。 本发明的光掩模基材是在真空紫外(VUV)波长区域中显示非常高的透射率的干直接沉积玻璃化硅氧氟化物玻璃,同时保持通常与高纯度熔融二氧化硅相关的优异的热和物理性能。 除了含氟且具有很少或不含OH含量之外,本发明的适用于157nm的光掩模衬底的直接沉积玻璃化氟氧化硅玻璃的特征还在于具有小于1×10 17分子/ cm 3的分子氢和低氯水平。
Abstract:
Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine. Laser and induction methods and apparatus for forming the barrier layer are depicted. A chlorine, fluorine and silica precursor, such as chlorofluorosilane, may be utilized to form fluorinated soot. Other methods and apparatus are directed to combinations of conventional and substantially water-free processes. One embodiment is directed to combustion enhancing additives for addition to the substantially hydrogen-free fuels. The methods and apparatus in accordance with the invention are particularly useful for producing photomask substrates and optical fiber preforms.
Abstract:
A process of manufacturing a silica glass article comprising the steps of: (1) irradiating a silica glass article with electromagnetic waves to generate defects therein; and (2) immersing the thus irradiated silica glass article in an atmosphere comprising a hydrogen gas, thereby providing the resulting silica glass article with a characteristic that is effective for preventing it substantially from increasing its absorption within an ultraviolet region due to ultraviolet ray irradiation. Also disclosed are a silica glass article or a glass fiber produced according to the manufacturing process.
Abstract:
A method is provided for manufacturing a silica glass that is substantially free of chlorine. The method includes the step of separately expelling a silicon tetrafluoride gas, a combustion gas, and a combustible gas from a burner made of silica glass, the flow velocity of the silicon tetrafluoride gas being within the range of about 9 slm/cm2 to about 20 slm/cm2. The method further includes the steps of producing minute silica glass particles by reacting the silicon tetrafluoride gas with water produced by a reaction of the combustion gas with the combustible gas, depositing the minute silica glass particles on a target, and producing the silica glass by fusing and vitrifying the minute silica glass particles deposited on the target.
Abstract:
In a known optical component a cylindrical glass core of synthetic quartz glass contains hydroxyl groups, a maximum 200 wt.-ppm of chlorine, and no dopant in the form of a metal oxide. The glass core is axially enveloped by a glass mantle of doped quartz glass which has a lower refractive index than the glass core. Setting out from this, in order to offer an optical component of quartz glass for broad-band transmission, especially for broad-band spectroscopy, which is characterized by low attenuation over a broad range of wavelengths, it is proposed by the invention that the core glass contain less than 5 wt.-ppm of hydroxyl groups.