OPTICAL FIBER

• US 20110274396A1
• Filed: 05/05/2011
• Published: 11/10/2011
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: NAKAJIMA, Yasuo, Tanaka, Hiroki, Mochizuki, Kouji, Arashitani, Yoshihiro
• Granted Patent: US 8,571,372 B2
• Time in Patent Office: Days
• US Class Current: 385/114
• CPC Class Codes: G02B 6/02395 Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104
• CPC Class Codes: G02B 6/4403 with ribbon structure G02B6/4429, G02B6/4439, G02B6/4479 take precedence
• CPC Class Codes: G02B 6/4482 Code or colour marking

Abstract

The present invention provides an optical fiber in which the transmission loss increase is suppressed even under a high-humidity condition or under a water-immersed condition. A colored optical fiber (22) according to an embodiment of the present invention is a colored optical fiber (22) formed by applying a colored layer to an optical fiber (14) including a glass optical fiber coated with at least a double-layered coating layer of a soft layer and a hard layer, and the ratio of thermal expansion coefficient between the coating layer after the colored layer of the colored optical fiber (22) is applied and the coating layer of the optical fiber (14) before the colored layer is applied is 0.87 or more. Furthermore, an optical fiber ribbon (32) according to another embodiment of the present invention is an optical fiber (32) formed by arranging a plurality of the colored optical fiber (22) in the form of a plane and coating them all together with a ribbon resin and the ratio of thermal expansion coefficient between the coating layer after the colored layer of the colored optical fiber (22) is applied and the coating layer of the optical fiber before the colored layer is applied is 0.90 or more.

Claims

1. A colored optical fiber comprising:

an optical fiber having at least a double-layered coating layer of a soft layer and a hard layer and a glass optical fiber coated with the coating layer; and

a colored layer which coats the optical fiber and which is formed by being applied to the optical fiber, wherein

a coating layer of the colored optical fiber is formed by the coating layer and the colored layer, and

a ratio of thermal expansion coefficient of the coating layer of the colored optical fiber after the colored layer is applied relative to the thermal expansion coefficient of the coating layer of the optical fiber before the colored layer is applied is 0.87 or more.

2. An optical fiber ribbon formed by arranging a plurality of the colored optical fibers according to claim 1 in the form of a plane and coating the plurality of the colored optical fiber all together with a ribbon resin, wherein

the ratio of thermal expansion coefficient of the coating layer of the colored optical fiber after the colored layer is applied relative to the thermal expansion coefficient of the coating layer of the optical fiber is 0.90 or more.