Patent ID: 7529453

Claim:
An optical fiber including a core region and a cladding region, wherein the cladding region includes a first cladding region on an outer circumference of the core region, the first cladding region consisting of a main-medium region and a sub-medium region, a refractive index of the sub-medium region being lower than a refractive index of the main-medium region, the sub-medium region includes a plurality of inner sub-medium regions arranged along the outer circumference of the core region and a plurality of outer sub-medium regions arranged on an outer side of the inner sub-medium regions along the outer circumference of the core region, and a lateral cross section of the outer sub-medium regions is larger than a lateral cross section of the inner sub-medium regions, wherein a macro-bending loss with a curvature radius of 5.0 millimeters at a wavelength of 1550 nanometers is equal to or less than 0.1 decibel per meter.