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AssigneeBell Telephone Laboratories, Incorporated
InventorsRobert L. Barns, Edwin A. Chandross
Estimating the term…
The presence of hydroxyl impurities (--OH) in optical fiber precursor materials produces optical losses in fibers made from the precursor material, as in the modified chemical vapor deposition process. Typical precursor materials include SiCl.sub.4, GeCl.sub.4, POCl.sub.3, and PCl.sub.3. Losses due to --OH impurities occur near various wavelengths of current interest for optical communications systems. Adding chlorine and PCl.sub.3 to impure SiCl.sub.4, GeCl.sub.4, or POCl.sub.3 reduces the amount of --OH impurities and produces POCl.sub.3 and HCl. The HCl may be readily removed, while the POCl.sub.3 is typically left in the material. Bromine may be used instead of chlorine, and PBr.sub.3 may be used instead of PCl.sub.3. In addition, --OH impurities in PCl.sub.3 may be removed by the addition of chlorine or bromine, with the resulting HCl or HBr typically being removed.
A method of reducing the amount of hydroxyl (--OH) containing impurities in an impure liquid chloride selected from the group consisting of SiCl.sub.4, GeCl.sub.4, and POCl.sub.3, CHARACTERIZED by reacting with said impure chloride a mixture of a first reactant selected from the group consisting of PCl.sub.3 and PBr.sub.3 and a second reactant selected from the group consisting of chlorine and bromine.
A method of reducing the amount of hydroxyl (--OH)-containing impurities in impure PCl.sub.3 CHARACTERIZED by reacting Cl.sub.2 or Br.sub.2 impure PCl.sub.3.
Dependencies are inferred from the claim text.