Abstract: The present invention relates to an optical fiber accommodated in an optical fiber cable, and more particularly, to an optical fiber which optimizes optical fiber coating resin and color resin and restrains an increase in transmission loss of the optical fiber due to an operating environment and aged deterioration and provides an optical fiber and optical fiber ribbon without any increase of transmission loss irrespective of the operating environment and aged deterioration, and especially when exposed to water or high humidity. The optical fiber is an optical fiber coated with at least two layers of coating resin, wherein the outermost coated coating resin is a colored layer made of color resin and when the optical fiber is immersed in water which is heated to 60° C. for 168 hours, an extraction rate of the coating resin of the optical fiber is set to 1.5 mass percent or below.

Abstract: An optical fiber holding apparatus in accordance with the present invention is characterized in that the same comprises a surface in order to hold an optical fiber which is to be a state of which is rolled up so as not to overlap with each other, wherein at least the surface is formed of a thermo conductive molding body which has a thermal conductivity to be higher than or equal to 0.5 W/mK, and which has an Asker C hardness to be between twenty and fifty. Or, the same comprises a peripheral surface in order to roll up and hold an optical fiber, wherein at least the peripheral surface is formed of a thermo conductive molding body which has the thermal conductivity to be higher than or equal to 0.5 W/mK, and which has the Asker C hardness to be between twenty and fifty. Moreover, it is desirable for the thermo conductive molding body to have a compressive strength of which a peak value is between ten and thirty N/cm2 and a stabilized value is between three and ten N/cm2.

Abstract: An optical fiber is provided, which is unlikely to cause interlayer delamination between a glass optical fiber and a primary coating layer even when it is immersed in water. The optical fiber of the present invention includes a glass optical fiber 1 consisting of a core and a cladding, a primary coating layer 2 overlaid on the glass optical fiber, and a secondary coating layer 3 overlaid on the primary coating layer, wherein the relaxation modulus of the secondary coating layer is set at 400 MPa or less.

Abstract: The present invention provides an optical fiber in which composites constructing its coating are not complicated, so, there is also little constraint in view of production, and, moreover, delamination between a glass optical fiber and a primary layer, and a bubble in the primary layer hardly arise. The optical fiber of the present invention is an optical fiber which has a glass optical fiber which has a core 1, which passes an optical signal, in a center portion, and a cladding 2 surrounding this, a primary protective layer 3 made to coat the glass optical fiber, a secondary protective layer 4 applied on this primary protective layer 3, and a third protective layer 5 applied to an outer periphery of this secondary protective layer 4, wherein glass transition temperature of the primary protective layer 3 is made to be higher than ?20° C. and 10° C. or lower, glass transition temperature of the secondary protective layer 4 is made to be ?10° C.

Abstract: An optical fiber is provided, which is unlikely to cause interlayer delamination between a glass optical fiber and a primary coating layer even when it is immersed in water. The optical fiber of the present invention includes a glass optical fiber 1 consisting of a core and a cladding, a primary coating layer 2 overlaid on the glass optical fiber, and a secondary coating layer 3 overlaid on the primary coating layer, wherein the relaxation modulus of the secondary coating layer is set at 400 MPa or less.

Abstract: The present invention relates to an optical fiber accommodated in an optical fiber cable, and more particularly, to an optical fiber which optimizes optical fiber coating resin and color resin and restrains an increase in transmission loss of the optical fiber due to an operating environment and aged deterioration and provides an optical fiber and optical fiber ribbon without any increase of transmission loss irrespective of the operating environment and aged deterioration, and especially when exposed to water or high humidity. The optical fiber is an optical fiber coated with at least two layers of coating resin, wherein the outermost coated coating resin is a colored layer made of color resin and when the optical fiber is immersed in water which is heated to 60° C. for 168 hours, an extraction rate of the coating resin of the optical fiber is set to 1.5 mass percent or below.

Abstract: There are provided an optical fiber ribbon and optical fiber cable which suppress the deterioration of polarization mode dispersion and contribute to the increase of communication capacity in wavelength division multiplexing. An optical fiber ribbon includes a plurality of optical fibers 12 tied in a bundle and a ribbon coating layer 13 formed around the plurality of optical fibers to integrate the plurality of optical fibers, wherein the glass-transition temperature of the coating ranges from 80° C. to 130° C. and “a” is 0.01 mm2 or less, where “a” is a sectional area of the ribbon coating layer 13 in a cross section in which outer half of the optical fiber at an edge of the ribbon and the coating of the optical fiber ribbon are taken along a line passing the center of the glass optical fiber positioned at one of edges of the ribbon out of the plurality of the optical fibers and being perpendicular to the horizontal plane of the optical fiber ribbon.

Abstract: An optical fiber ribbon and an optical fiber cable capable of suppressing deterioration of polarization mode dispersion and effective in improving the communication capacity in wavelength multiplex communication. In an optical fiber ribbon having a plurality of optical fibers 12 in a bundled form, and a ribbon coating layer 13 formed around the plurality of optical fibers so as to integrally combining the plurality of optical fibers, the glass transition temperature of the ribbon coating is within the range from 80 to 130° C.; the Young's modulus of the ribbon coating is within the range from 800 to 2100 MPa; the thickness a of the ribbon coating layer applied on the upper and lower sides of the plurality of optical fibers and the thickness b of the ribbon coating layer applied outside the optical fibers in the outermost positions in the optical fiber ribbon always satisfy 1<b/a?2; the ribbon coating layer thickness a is 10 ?m or less; and the ribbon coating layer thickness b is smaller than 20 ?m.

Abstract: The present invention provides an optical fiber for a fiber Bragg grating having a high reliability and superior performance. An optical fiber according to the present invention has a glass film containing micro porous bodies formed on the circumference of the optical fiber having a photosensitive core or both of the photosensitive core and a cladding.

Abstract: There are provided an optical fiber ribbon and optical fiber cable which suppress the deterioration of polarization mode dispersion and contribute to the increase of communication capacity in wavelength division multiplexing. An optical fiber ribbon includes a plurality of optical fibers 12 tied in a bundle and a ribbon coating layer 13 formed around the plurality of optical fibers to integrate the plurality of optical fibers, wherein the glass-transition temperature of the coating ranges from 80° C. to 130° C. and “a” is 0.01 mm2 or less, where “a” is a sectional area of the ribbon coating layer 13 in a cross section in which outer half of the optical fiber at an edge of the ribbon and the coating of the optical fiber ribbon are taken along a line passing the center of the glass optical fiber positioned at one of edges of the ribbon out of the plurality of the optical fibers and being perpendicular to the horizontal plane of the optical fiber ribbon.