METHOD OF MANUFACTURING FLUORINE DOPED SILICA GLASS ARTICLE, AND METHOD OF MANUFACTURING OPTICAL FIBER PREFORM AND OPTICAL FIBER USING THE METHOD, AND OPTICAL FIBER MADE BY SUCH METHOD

摘要

Provided are an optical fiber which exhibits a small increment of loss due to the OH group and which is suitable for transmitting signals in a band including a wavelength of 1,380 nm, and methods for manufacturing such optical fiber, an optical fiber preform, and a fluorine doped silica glass article. The fluorine doped silica glass article is produced by (1) depositing silica glass soot on a starting substrate to produce a silica glass soot deposit body and (2) heating the silica glass soot deposit body in an atmosphere including at least a first gas containing fluorine atoms and a second gas having deoxidizing property and containing no fluorine atom nor hydrogen atom. An optical fiber preform and an optical fiber are produced by the use of this glass body. The optical fiber has a clad containing fluorine and exhibits a transmission loss of 0.32 dB/km or less at a wavelength of 1,380 nm.