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:
May. 18, 2021
Filed:
Nov. 27, 2019
Fujikura Ltd., Tokyo, JP;
Takayuki Kitamura, Chiba, JP;
Akihito Imase, Chiba, JP;
Fujikura Ltd., Tokyo, JP;
Abstract
An optical fiber production method includes: drawing an optical fiber preform in a drawing furnace; and cooling the optical fiber. The optical fiber is passed through a plurality of annealing furnaces while the optical fiber is cooled. While the optical fiber is cooled, temperatures of the annealing furnaces are set such that the temperature difference is within a range between and including an upper limit and a lower limit of a temperature difference between a temperature of the optical fiber and a fictive temperature of glass constituting a core of the optical fiber at which an increase of a transmission loss of the optical fiber when the fictive temperature of the glass is decreased is less than 0.001 dB/km.