Coated optical fiber and manufacturing method and apparatus therefor

A method of manufacturing a coated optical fiber, comprising the steps of:

• making a coated optical fiber by forming an outer coating layer around a bare optical fiber;
• and
• winding the coated optical fiber via pulleys by a take-up,
• wherein when at least one of the conditions that the temperature of the outer coating layer is a room temperature and the Young's modulus of the outer coating layer is higher than 500 MPa is satisfied, the surface roughness of each solid body, which the outer layer of the coated optical fiber contacts during drawing or rewinding, is 1.2 μm or less.

An apparatus for manufacturing a coated optical fiber, comprising:

• a drawing furnace for melting an optical fiber preform and forming a bare optical fiber;
• a cooling system for cooling the formed bare optical fiber;
• a resin coating system for coating the bare optical fiber with resin which functions as an outer coating layer of the coated optical fiber;
• a curing system for curing the resin;
• and
• pulleys arranged in a path line along which the coated optical fiber is transferred to a take-up,
• wherein the surface roughness of each solid body which the outer layer of the running coated optical fiber contacts is 0.8 μm or less.

An apparatus for manufacturing a coated optical fiber, comprising:

• a drawing furnace for melting an optical fiber preform and forming a bare optical fiber;
• a cooling system for cooling the formed bare optical fiber;
• a resin coating system for coating the bare optical fiber with resin which functions as an outer coating layer of the coated optical fiber;
• a curing system for curing the resin;
• and
• pulleys arranged in a path line along which the coated optical fiber is transferred to a take-up,
• wherein when at least one of the conditions that the temperature of the outer coating layer is a room temperature and the Young's modulus of the outer coating layer is higher than 500 MPa is satisfied, the surface roughness of each solid body which the outer layer of the coated optical fiber contacts is 1.2 μm or less.