Abstract: A method for manufacturing an optical fiber includes: exposing a glass fiber by stripping a fiber coating layer at an end portion, on a splicing side, of each of a pair of optical fibers; fusion-splicing the glass fibers; and recoating a protective resin on a periphery of exposed portions of the glass fibers. The fiber coating layer includes a primary resin layer on an inner peripheral side and having a Young's modulus of 0.5 MPa or less and a secondary resin layer on an outer peripheral side and having a Young's modulus of 800 MPa or greater, the exposing includes forming a shape of a coating edge of the fiber coating layer which includes the primary resin layer and the secondary resin layer into a tapered shape which becomes narrower toward the end portion side, and the recoating includes coating the protective resin to include the coating edge.

Abstract: A method for manufacturing an optical fiber includes: exposing a glass fiber by stripping a fiber coating layer at an end portion, on a splicing side, of each of a pair of optical fibers; fusion-splicing the glass fibers; and recoating a protective resin on a periphery of exposed portions of the glass fibers. The fiber coating layer includes a primary resin layer on an inner peripheral side and having a Young's modulus of 0.5 MPa or less and a secondary resin layer on an outer peripheral side and having a Young's modulus of 800 MPa or greater, the exposing includes forming a shape of a coating edge of the fiber coating layer which includes the primary resin layer and the secondary resin layer into a tapered shape which becomes narrower toward the end portion side, and the recoating includes coating the protective resin to include the coating edge.

Abstract: The present embodiment relates to an optical fiber line or the like configured by connecting a single-mode optical fiber with a cladding containing fluorine and a large Aeff optical fiber by TEC connection, and a connection state between such two types of optical fibers is set such that a connection loss expressed in dB of a fundamental mode is equal to or less than 55% of an ideal butt loss expressed in dB at a wavelength of 1550 nm.

Abstract: The present embodiment relates to an optical fiber line or the like configured by connecting a single-mode optical fiber with a cladding containing fluorine and a large Aeff optical fiber by TEC connection, and a connection state between such two types of optical fibers is set such that a connection loss expressed in dB of a fundamental mode is equal to or less than 55% of an ideal butt loss expressed in dB at a wavelength of 1550 nm.

Abstract: A method of manufacturing multi-mode optical fiber is disclosed. The method of manufacturing includes: a step of forming a first glass base material while controlling a supply rate of an additive for adjusting a refractive index to achieve a desired refractive index distribution; a step of drawing the first glass base material; a step of measuring a residual stress distribution in a radial direction of the multi-mode optical fiber after being drawn; a step of readjusting the supply rate of the additive in accordance with deviation of a refractive index, acquired from the residual stress distribution measured, from the desired refractive index distribution; a step of forming a second glass base material while supplying the additive at the supply rate after being readjusted; and a step of drawing the second glass base material.

Abstract: A method of manufacturing multi-mode optical fiber is disclosed. The method of manufacturing includes: a step of forming a first glass base material while controlling a supply rate of an additive for adjusting a refractive index to achieve a desired refractive index distribution; a step of drawing the first glass base material; a step of measuring a residual stress distribution in a radial direction of the multi-mode optical fiber after being drawn; a step of readjusting the supply rate of the additive in accordance with deviation of a refractive index, acquired from the residual stress distribution measured, from the desired refractive index distribution; a step of forming a second glass base material while supplying the additive at the supply rate after being readjusted; and a step of drawing the second glass base material.