Method of measuring bending performance of optical fiber

A method for measuring bending performance of an optical fiber comprising:

• a first step of measuring power P0 of light emitted from an end of an optical fiber when light is incident on the other end of the optical fiber under conditions where no bend loss occurs in the optical fiber;
• a second step of winding the optical fiber around a mandrel with a diameter 2R and covering the overall outer circumference of such wound optical fiber with an index matching sheet and subsequently measuring power P1 of light emitted from one end of the optical fiber when light is incident on the other end of the optical fiber, whereas the refractive index of the index matching sheet substantially matches with the refractive index of resin in the outermost layer of the optical fiber;
• and
• a third step of measuring, based on the power P0 measured at the first step and the power P1 measured at the second step, bend loss of the optical fiber when the optical fiber is bent at the diameter 2R.