The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 04, 1983
Filed:
Sep. 19, 1980
Shoichi Suto, Mito, JP;
Fumiaki Hanawa, Mito, JP;
Masao Kawachi, Mito, JP;
Takao Edahiro, Mito, JP;
Motohiro Nakahara, Mito, JP;
Nippon Telegraph & Telephone Public Corporation, Tokyo, JP;
Abstract
A method of fabricating an optical fiber preform wherein a synthesizing torch is inclined between 10.degree. and 60.degree. with respect to the rotation axis of a seed rod. Moving the rod while rotating it, a glass raw material gas and a flame forming gas are blown out individually from the torch to synthesize glass particles which are deposited onto one end of the rod, so that a cylindrical porous preform is grown in the direction of the rotation axis of the rod. Then the porous preform is heated at a high temperature to vitrify the porous preform into a transparent optical fiber preform. At least one exhaust port is disposed at a distance of 1 mm to 50 mm from the periphery of the porous preform and in the vicinity of the growing surface of the porous preform. In fabricating the porous preform the outer diameter fluctuations are small, and the preform is formed stably without formation of cracking on the periphery of the preform.