Bent optical fiber, method for manufacturing bent optical fiber, and optical connection component

A bent optical fiber manufacturing method comprising:

• preparing an optical fiber to be processed which has a first end face and a second end face and comprises:
• a glass optical fiber including a core extending along a central axis from the first end face toward the second end face, a stress applying portion extending along the central axis for applying stress to the core, and a cladding covering the core and the stress applying portion;
• and a resin coating provided on an outer peripheral surface of the glass optical fiber;
• removing a portion of the resin coating for a predetermined length from the first end face to expose a portion of the glass optical fiber including the first end face;
• bending a portion of an exposed region, out of the glass optical fiber from which the portion of the resin coating has been removed, by heating a section away from the first end face;
• and
• cooling the section having been heated at a decreasing rate of 100° C./s or more until a surface temperature of the section decreases from a maximum temperature at a time of heating to 1000° C. or less.

A bent optical fiber manufacturing method comprising:

• preparing an optical fiber to be processed which has a first end face and a second end face and comprises:
• a glass optical fiber including a core extending along a central axis from the first end face toward the second end face, a stress applying portion extending along the central axis for applying stress to the core, and a cladding covering the core and the stress applying portion;
• and a resin coating provided on an outer peripheral surface of the glass optical fiber;
• removing a portion of the resin coating for a predetermined length from the first end face to expose a portion of the glass optical fiber including the first end face;
• and
• bending a portion of an exposed region, out of the glass optical fiber from which the portion of the resin coating has been removed, by heating a section away from the first end face, wherein
• in the bending, before heating the section away from the first end face, the exposed region is installed in a state in which a Slow-axis, which serves as a vibration direction in which propagation velocity is minimum on a cross-section of the glass optical fiber orthogonal to the central axis, intersects a bending plane, which includes a center of the core and defines a bending direction, at an angle θslow;
• and
• the section is heated along the bending plane so as to form a bent portion having a curvature of 0.1 (l/mm) or more while maintaining the angle θslow.