Optical fiber

Abstract

An optical fiber comprises a glass fiber comprising a core and a cladding; and a coating resin layer coating the glass fiber, wherein the coating resin layer has a primary resin layer in contact with the glass fiber and coating the glass fiber and a secondary resin layer coating the outer periphery of the primary resin layer, the primary resin layer has a Young's modulus of 0.4 MPa or less at 23° C. and the primary resin layer has an outer diameter of 185 μm or more and 202 μm or less, the secondary resin layer has a glass transition temperature of 60° C. or more and 95° C. or less, and the difference between the average linear expansion coefficient of the coating resin layer in the range of 60° C. to 140° C. and the average linear expansion coefficient of the coating resin layer in the range of −60° C. to 0° C. is 0.7×10−4/° C. or less.

Dependencies are inferred from the claim text.