Patent ID: 9746605
Date: 2017-08-29
CPC Classifications: G02B

Claim:
1. An optical fiber comprising: an optical transmission member including a core and a clad; a primary resin layer contacting with the optical transmission member and coating the optical transmission member; and a secondary resin layer coating the primary resin layer, wherein an effective area of the optical transmission member is 130 μm a Young's modulus of the primary resin layer is 0.7 MPa or lower, a Young's modulus of the secondary resin layer is 600 MPa or higher and 1500 MPa or lower, an outer diameter of the primary resin layer is 185 μm or longer and 220 μm or shorter, an outer diameter of the secondary resin layer is 225 μm or longer and 260 μm or shorter, and a difference between the transmission loss when the optical fiber is wound at a tension of 80 g around a bobbin on which a metal mesh member having vertical wires of a 50-μm diameter and horizontal wires of a 50-μm diameter are wound and spaced at a pitch of 150 μm, and the transmission loss of an optical fiber coil is 1.0 dB/km or smaller, the primary resin layer comprises urethane oligomers including a di-reactive termini oligomer and a mono-reactive terminus oligomer, and the mono-reactive terminus oligomer is included at 50% or more in the primary resin.