	US 12,030,808 B2
	Method for manufacturing an optical fiber
Kenji Yamashiro, Suzuka (JP); and Miryo Kashiwazaki, Suzuka (JP)
Assigned to Fujikura Ltd., Tokyo (JP)
Filed by Fujikura Ltd., Tokyo (JP)
Filed on Jan. 27, 2021, as Appl. No. 17/159,670.
Claims priority of application No. 2020-012701 (JP), filed on Jan. 29, 2020; and application No. 2020-206611 (JP), filed on Dec. 14, 2020.
Prior Publication US 2021/0230058 A1, Jul. 29, 2021
Int. Cl. C03C 25/26 (2018.01); C03C 25/106 (2018.01); C03C 25/12 (2006.01); C03C 25/607 (2018.01)

CPC C03C 25/12 (2013.01) [C03C 25/106 (2013.01); C03C 25/26 (2013.01)]

8 Claims

1. A method for manufacturing an optical fiber, the method comprising:

exposing a bare fiber having a temperature of 500° C. to 1,500° C. to a gas in which a moisture content is controlled to 2 to 20 g/m³, wherein the bare fiber is formed of glass;

applying an uncured resin to an outer periphery of the bare fiber; and

curing the resin to form a coating layer, wherein

any one of Expression (3), (4), or (5) is satisfied:

3≤W≤5 and 0.3≤T≤0.4 (3);

4≤W≤15 and 0.1≤T≤0.3 (4);

10≤W≤15 and 0.05≤T≤0.3 (5),

where

W (g/m³) is the moisture content of the gas, and

T (sec) is a time for exposing the bare fiber to the gas.