OPTICAL FIBER MANUFACTURING METHOD AND OPTICAL FIBER

摘要

An optical fiber manufacturing method and an optical fiber. The transmission loss is prevented from increasing by the prevention of entry of an OH group into the vicinity of a core portion. An optical fiber manufacturing method comprises attaching a ring portion (15) to the internal surface of a starting pipe (14) serving as a starting member so as to form a glass pipe (16), inserting a glass rod (13) to serve as both a center core (11) and a depressed portion (12) into the glass pipe(16), integrating the glass pipe (16) and the glass rod (13) by collapsing in order to form a glass body (17), providing a jacket portion (18) outside the glass body (17) to form a preform (10a), and drawing the perform (10a) to manufacture an optical fiber (10). Wall thickness (14a) of the starting pipe (14) is set to 4 to 8 mm.