Combined numerical and analytical method of calculating microbending losses in single-mode fibers with arbitrary index profiles

Using a multilayer approximation of the index distribution, analytical solutions of the microbending losses according to Petermann's approach for single-mode fibers with arbitrary index profiles can be derived. It is shown that less than 20 layers are required to ensure satisfying accuracy for graded-index single-mode fibers. For single-cladded fibers, simple profile-independent formulas for the ω
01
and ω
02
spots sizes are presented. These make it possible from the Laplace spot size at the zero dispersion wavelength to derive the spectral microbending losses without knowing the index profile.