Plastic optical fiber, hybrid cable, patch cord, and active optical cable

A plastic optical fiber comprising:

• a core;
• and
• a clad disposed on an outer circumference of the core, wherein
• the core includes a first resin,
• the clad includes a second resin,
• the first resin has a first glass transition temperature Tg1 of 120° C. or higher,
• the second resin has a second glass transition temperature Tg2 of 120° C. or higher,
• when the plastic optical fiber bent once 180 degrees at 25° C. has a curvature radius R and a minimum of the curvature radius R is defined as a curvature radius at which a crack does not occur in a bent portion of the plastic optical fiber, the minimum is less than 5 mm, and
• a fiber structure composed of the core and the clad has a birefringence of 2.0×10−4 or more.