The optical fiber provides single mode transmission and low bend loss.

Disclosed is an optical fiber improved in bend loss characteristics without having a hole.

Optical waveguide fiber that has large effective area and low loss characteristics, such as low attenuation and low bend loss.

Disclosed is an optical fiber wherein bend loss is reduced while maintaining large MFD.

Disclosed is an optical fiber wherein bend loss is reduced while maintaining large MFD.

This construction can effectively reduce a bending loss.

Thus, bending loss in the waveguide is substantially reduced.

Bending loss at a radius of curvature of 7.5 mm is smaller than 0.1 dB/turn for a wavelength of 1550 nm, and bending loss at a radius of curvature of 4 mm is larger than 0.1 dB/turn for a wavelength of 1625 nm.

The plastic optical fiber allows the achievement of a combination of low transmission loss, a high band, and a low bending loss in a broad wavelength region.

Provided is an optical fiber conforming to standard G.652 wherein the bending loss is small and breakage due to incidental bending at the time of laying work can be prevented.