Abstract: The invention is directed to a process of purifying metal fluoride materials used to make metal fluoride single crystals suitable for making optical elements used in the transmission of wavelengths below 200 nm, and in particular to a process of purifying such materials by the use of a halogen containing plasma to convert metal oxygenates contaminating the feedstocks used in the preparation of the crystals to metal fluorides. The invention also is directed to a process of growing a metal fluoride single crystal using a crystal growth furnace to carry out the foregoing purification procedure followed by the steps of melting the purified material and cooling it using s selected time and temperature cycle to from a metal fluoride single crystal.

Abstract: A method and apparatus for producing an optical fiber preform including a metal remover, which operates by adsorption, that removes gaseous transition metal impurities present in a process gas to be provided to a furnace for drying, doping or consolidation. The apparatus and method may reduce attenuation of the resultant optical fiber drawn from the preform.

Abstract: A method and apparatus for producing an optical fiber preform including a metal remover, which operates by adsorption, that removes gaseous transition metal impurities present in a process gas to be provided to a furnace for drying, doping or consolidation. The apparatus and method may reduce attenuation of the resultant optical fiber drawn from the preform.

Abstract: Disclosed is a method of making a hydrogen resistant optical waveguide fiber. The soot preform is heated and immersed in a metal halide gas. A reduced metal species is thus incorporated into the glass soot prior to sintering or consolidation of the soot preform. A hydrogen absorption band around 1530 nm is substantially eliminated from waveguides made from a precursor gas treated preform.

Abstract: A method for manufacturing optical fiber preform and fiber. According to the method, a core cane segment is formed with a refractive index delta preferably between 0.2% and 3% that is most preferably formed by an OVD method. A sleeve is formed including at least one down-doped moat preferably having a refractive index delta between −0.1% and −1.2% and at least one up-doped ring preferably having a refractive index delta between 0.1% and 1.2%. The sleeve is formed by introducing glass precursor and dopant compounds into a cavity of a preferably silica glass tube (e.g., one of an MCVD and PCVD method). The core cane segment is inserted into the sleeve and the sleeve is collapsed onto the core cane segment to form a core-sleeve assembly. The core-sleeve assembly is again drawn into a cane and additional cladding is preferably formed thereon. Optical fiber may be drawn from the preform in a conventional draw apparatus.

Abstract: A method for manufacturing optical fiber preform and fiber. According to the method, a core cane segment is formed with a refractive index delta preferably between 0.2% and 3% that is most preferably formed by an OVD method. A sleeve is formed including at least one down-doped moat preferably having a refractive index delta between −0.1% and −1.2% and at least one up-doped ring preferably having a refractive index delta between 0.1% and 1.2%. The sleeve is formed by introducing glass precursor and dopant compounds into a cavity of a preferably silica glass tube (e.g., one of an MCVD and PCVD method). The core cane segment is inserted into the sleeve and the sleeve is collapsed onto the core cane segment to form a core-sleeve assembly. The core-sleeve assembly is again drawn into a cane and additional cladding is preferably formed thereon. Optical fiber may be drawn from the preform in a conventional draw apparatus.

Abstract: A cylindrical glass body having a low water content centerline region and method of manufacturing such a cylindrical glass body for use in the manufacture of optical waveguide fiber is disclosed. The centerline region of the cylindrical glass body has a water content sufficiently low such that an optical waveguide fiber made from the cylindrical glass body of the present invention exhibits an optical attenuation of less than about 0.35 dB/km, and preferably less than about 0.31 dB/km at a measured wavelength of 1380 nm. A low water content plug used in the manufacture of such a cylindrical glass body, an optical waveguide fiber having a low water peak, and an optical fiber communication system incorporating such an optical waveguide fiber is also disclosed.

Abstract: Disclosed is a method of making a hydrogen resistant optical waveguide fiber. The soot preform is heated and immersed in a metal halide gas. A reduced metal species is thus incorporated into the glass soot prior to sintering or consolidation of the soot preform. A hydrogen absorption band around 1530 nm is substantially eliminated from waveguides made from a precursor gas treated preform.

Abstract: Disclosed is a method of making a hydrogen resistant optical waveguide fiber. The soot preform is heated and then immersed in a GeCl4 gas. A reduced metal species is thus incorporated into the glass soot prior to sintering or consolidation of the soot preform. A hydrogen absorption band around 1530 nm is substantially eliminated from waveguides made from a precursor gas treated preform.