OPTICAL FIBER

摘要

An optical fiber having a first covering (2) surrounding the optical fiber (1) and a second covering (3) surrounding the first covering, the first covering comprising a material, the Young's modulus of which at -30 DEG C is not greater than ten times that at 23 DEG C, which has small increase of attenuation of light transmission at a low temperature and also small increase of attenuation of light transmission due to lateral pressure not only at a room temperature but also at a low temperature.