Method for manufacturing optical fiber and optical fiber

A method for manufacturing an optical fiber comprising:

• melting an optical fiber preform and drawing a glass fiber;
• applying a resin composition to an outer periphery of the glass fiber;
• and
• curing the resin composition applied,
• wherein an amount of eccentricity of a central axis of the glass fiber, in a cross section perpendicular to the central axis of the glass fiber, from a central axis relative to an outer periphery of the resin composition or an outer periphery of a coating resin layer formed by curing the resin composition is measured at 50 points or more over a length range of 50 m or more of the glass fiber at a sampling period of 20 ms or less,
• wherein the resin composition is applied such that a mean value a and a standard deviation σ of the amount of eccentricity satisfy a+3σ≤10 μm,
• wherein the resin composition is applied such that a histogram of the amount of eccentricity is unimodal when a class width is 1 μm, and
• wherein the resin composition is applied while adjusting at least one of
• (A) a position or a tilt of an application device for applying the resin composition;
• and
• (B) a position of the optical fiber preform, or a position of a roller disposed directly below a curing device and configured to change a running direction of the optical fiber, the curing device being configured to cure the resin composition.