| abstract |
An optical fiber comprises a glass fiber comprising a core and a cladding, a primary resin layer being in contact with the glass fiber and covering the glass fiber, and a secondary resin layer covering the primary resin layer, wherein the Young's modulus of the primary resin layer is 0.04 MPa or more and 1.0 MPa or less at 23°C ± 2°C, the secondary resin layer consists of a cured product of a resin composition comprising a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator and hydrophobic inorganic oxide particles, and the content of the inorganic oxide particles is 1% by mass or more and 60% by mass or less based on the total amount of the resin composition. |