Analytical bending loss formula of optical fibers with field deformation

Bending losses in a radially inhomogeneous profile fiber were studied, taking into account bend‐induced field deformation to the first‐order perturbation. Analytical bending loss formulas are given for arbitrary mode numbers in step‐index fibers. Polarization degeneracy in bending loss still exists even when field deformation effects are taken into account. The bending loss in a step‐index single‐mode fiber increases by 36% at υ = 2.4 and ℜ = R Δ/a = 10 as compared with that without field deformation.