Abstract: An optical fiber includes: a core made of silica based glass; a cladding made of silica based glass, the cladding having a refractive index that is lower than a maximum refractive index of the core; and a coating including a primary coating layer, and a secondary coating layer. An outer diameter of the cladding is less than 100 ?m. A thickness of the primary coating layer is larger than or equal to 15 ?m. A mode field diameter at a wavelength of 1310 nm is larger than or equal to 8.6 ?m and smaller than or equal to 9.2 ?m. An effective cutoff wavelength is smaller than or equal to 1260 ?m. A bending loss at a wavelength of 1550 nm when bending is made at a diameter of 60 mm is smaller than or equal to 0.1 dB/100 turn.

Abstract: An optical fiber includes: a core made of silica-based glass; a cladding configured to cover an outer circumference of the core and made of silica-based glass having a refractive index smaller than a maximum refractive index of the core; and a coating configured to cover an outer circumference of the cladding. The cladding has an outer diameter of 120 ?m or smaller, a mode field diameter at a wavelength of 1310 nm is 8.6 ?m to 9.2 ?m, an effective cut-off wavelength is 1260 ?m or smaller, and a bending loss at a wavelength of 1550 nm in a case of bending at a diameter of 20 mm is 0.75 dB/turn or smaller.

Abstract: An optical fiber includes: a core portion made of glass; a side core layer made of glass and enclosing the core portion; a cladding portion made of glass and enclosing the side core layer; and a coating layer including a primary layer made of resin and enclosing the cladding portion, and a secondary layer made of resin and enclosing the primary layer. The relationships ?1>?Clad>?2 and 0>?2 are satisfied where ?1 represents relative refractive-index difference of average maximum refractive index of the core portion with respect to average refractive index of the cladding portion, ?2 represents relative refractive-index difference of average refractive index of the side core layer with respect to average refractive index of the cladding portion, and ?Clad represents relative refractive-index difference of average refractive index of the cladding portion with respect to refractive index of pure silica glass.

Abstract: An optical fiber manufacturing method includes: a drawing step of heating one end portion of an optical fiber preform to melt and deform the one end portion and drawing an optical fiber, wherein in the drawing step, drawing is performed while applying pressure to a melted-deformed portion that is melted and deformed.

Abstract: An optical fiber includes: a core made of silica based glass; a cladding made of silica based glass, the cladding having a refractive index that is lower than a maximum refractive index of the core; and a coating including a primary coating layer, and a secondary coating layer. An outer diameter of the cladding is less than 100 ?m. A thickness of the primary coating layer is larger than or equal to 15 ?m. A mode field diameter at a wavelength of 1310 nm is larger than or equal to 8.6 ?m and smaller than or equal to 9.2 ?m. An effective cutoff wavelength is smaller than or equal to 1260 ?m. A bending loss at a wavelength of 1550 nm when bending is made at a diameter of 60 mm is smaller than or equal to 0.1 dB/100 turn.

Abstract: An optical fiber includes: a core made of silica-based glass; a cladding configured to cover an outer circumference of the core and made of silica-based glass having a refractive index smaller than a maximum refractive index of the core; and a coating configured to cover an outer circumference of the cladding. The cladding has an outer diameter of 120 ?m or smaller, a mode field diameter at a wavelength of 1310 nm is 8.6 ?m to 9.2 ?m, an effective cut-off wavelength is 1260 ?m or smaller, and a bending loss at a wavelength of 1550 nm in a case of bending at a diameter of 20 mm is 0.75 dB/turn or smaller.

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: 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.