FIBER FOR OPTICAL TRANSMISSION

摘要

An optical fiber comprises a first covering surrounding the optical fiber and a second covering surrounding the first covering, the first covering comprising a material with Young's modulus at -30OC not greater than ten times that at 23OC. Specifically, the first covering comprises an UV or electron beam cured resin, having a Young's modulus at 23OC of 0.5 kg/mm2 or less. The second covering comprises a thermoplastic resin. Tight structure optical fiber in which increase of attenuation or light transmission at a low temp. is small by using a first covering whose young's modulus is less temp. dependent and which has only a small increase of attenuation of light transmission due to external force at a low temp.