Abstract: The present invention satisfies at least one of the condition of the degree of freedom of a primary layer 11 shown in the equation (I) and the condition of the rigidity of a secondary layer 12 shown in the equation (II). Thus, a coated optical fiber 1 capable of suppressing transmission loss in a low temperature environment is provided, in which, even when an optical fiber 10 having a large effective core cross-sectional area Aeff of the optical fiber 10 at a wavelength of 1550 nm and having high microbend sensitivity is used, transmission loss in a low temperature environment can be suppressed. [Math.

Abstract: The present invention satisfies at least one of the condition of the degree of freedom of a primary layer 11 shown in the equation (I) and the condition of the rigidity of a secondary layer 12 shown in the equation (II). Thus, a coated optical fiber 1 capable of suppressing transmission loss in a low temperature environment is provided, in which, even when an optical fiber 10 having a large effective core cross-sectional area Aeff of the optical fiber 10 at a wavelength of 1550 nm and having high microbend sensitivity is used, transmission loss in a low temperature environment can be suppressed. [Math.

Abstract: Provided is a coated optical fiber and an optical fiber cable capable of suppressing transmission loss (microbend loss) even in an optical fiber having high microbend sensitivity. In the present invention, the degree of freedom of a primary layer 11 represented by the equation (I) and the rigidity of a secondary layer 12 represented by the equation (II) are set in specific ranges, respectively. Thus, the present invention provides a coated optical fiber 1 capable of suppressing the transmission loss even when an optical fiber 10 having high microbend sensitivity such as a BI fiber having a large effective core cross-sectional area Aeff of an optical fiber is used. The present invention can be widely used as a coated optical fiber 1 constituting a coated optical fiber ribbon or as a coated optical fiber 1 housed in an optical fiber cable. Further, an optical fiber cable including such coated optical fibers 1 enjoys the effect of the above-described coated optical fiber 1. [Math.

Abstract: Provided is a coated optical fiber and an optical fiber cable capable of suppressing transmission loss (microbend loss) even in an optical fiber having high microbend sensitivity. In the present invention, the degree of freedom of a primary layer 11 represented by the equation (I) and the rigidity of a secondary layer 12 represented by the equation (II) are set in specific ranges, respectively. Thus, the present invention provides a coated optical fiber 1 capable of suppressing the transmission loss even when an optical fiber 10 having high microbend sensitivity such as a BI fiber having a large effective core cross-sectional area Aeff of an optical fiber is used. The present invention can be widely used as a coated optical fiber 1 constituting a coated optical fiber ribbon or as a coated optical fiber 1 housed in an optical fiber cable. Further, an optical fiber cable including such coated optical fibers 1 enjoys the effect of the above-described coated optical fiber 1. [Math.