Bending Losses of Coated Single-Mode Optical Fibers

Peaks appear in bending losses of coated single-mode fibers due to interference between the guided mode and rays which are radi- ated from the guided mode and are reflected at cladding-coating bound- ary. This paper reports derivation of bending loss formulas for coated slab waveguides and coated fibers. Plane wave concepts are also used to explain the appearance of the loss peaks. Measurements were performed by using two coated single-mode fibers. The agreement between theory