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. 31, 1989
Filed:
May. 27, 1987
Nippon Telegraph & Telephone Corporation, Tokyo, JP;
Abstract
In an optical fiber preform fabrication method having the steps of decomposing a glass raw material in a flame so that fine glass particles are produced; depositing the fine glass particles on a seed rod to form a porous preform; and consolidating the porous preform into a transparent optical fiber preform, use is made of a burner having a raw material supply orifice for supplying the glass raw material and a plurality of flame forming orifices deposed around the raw material supply orifice sequentially for forming a plurality of flames, respectively. The flame speed V.sub.k of a kth flame, the flame speed V.sub.k+1 of a (k+1)th flame surrounding outwardly of the kth flame and the flow speed Vm of the glass raw material are determined in a suitable manner. The glass raw material is supplied to the multi-flame produced by the burner in which the kth flame is positioned rearwardly of the (k+1)th flame to synthesize the fine glass particles.