Abstract: A passively aligned optical isolator includes laminated layers of material including two polarizing glass layers sandwiching a Faraday rotator layer. Each polarizing glass layer comprises a glass matrix containing elongated metal particles exhibiting a change in polarization axis of less than about 0.0375°/m over a distance of at least 8 mm, as measured across a major surface of the layer. The optical isolator has a contrast ratio greater than 40 dB.

Abstract: Polarizing glass articles, optical isolators including polarizing glass articles, and methods of manufacturing polarizing glass articles and optical isolators are disclosed. The methods manufacture can be used to manufacture isolators exhibiting improved contrast ratio.

Abstract: A fused silica production furnace and methods of producing fused silica are disclosed. The furnace and the methods involve using a foamed refractory having a network of interconnected pores.

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 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: Methods for improving the strength of alumina refractory materials are disclosed. The method involves exposing the alumina material to a halogen gas. The treated materials can be used in furnaces for producing fused silica optical members.

Abstract: A method and furnace are described for producing a fused oxide body by decomposing a precursor compound of the oxide in a flame to form molten oxide particles and collecting those particles in a furnace constructed of a refractory material to form a fused oxide body, the improvement in the method comprising treating the refractory material with a strong acid in liquid form to react with, and thereby remove, contaminants from at least the surface of the refractory material.

Abstract: An article of relatively pure silica, and a furnace and method of producing the article. The article is produced by collecting molten silica particles in a refractory furnace in which at least a portion of the refractory has been exposed to a halogen-containing gas to react with contaminating metal ions in the refractory.

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 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: An article of relatively pure silica, and a furnace and method of producing the article. The article is produced by collecting molten silica particles (24) in a refractory furnace in which at least a portion of the refractory has been exposed to a halogen-containing gas to react with contaminating metal ions in the refractory.

Abstract: A method of producing, by flame hydrolysis, a fused silica glass containing titania which comprises delivering a mixture of a silica precursor and a titania precursor in vapor form to a flame, passing the vapor mixture through the flame to form SiO.sub.2 --TiO.sub.2 particles, and depositing the particles within a furnace where they melt to form a solid glass body.

Abstract: A method of producing a sintered glass article from a fritted glass body, and preventing the body from adhering to a refractory carrier during the sintering step which comprises coating the refractory carrier with a thin, continuous layer of yttrium oxide.