Simple approximations for chromatic dispersion in single- mode fibers with various index profiles

Simple approximate formulas of chromatic dispersion and zero-chromatic dispersion wavelength are empirically derived for single-mode fibers with various index profiles having the deformations such as a central dip, hump, and/or tailing at a core cladding interface. These profiles are typical which are commonly obtained in current single-mode fibers. The approximation is based on the exact solution of vector-wave equation. These accuracies are better than 0.3 and 0.03 percent for the chromatic dispersion and zero-chromatic dispersion wavelength, respectively. With the aid of the simple approximations, the properties of chromaric dispersion and zero-chromatic dispersion wavelength for practical single-mode fibers are discussed. The relation between the chromatic dispersion and basic fiber parameters of single-mode fibers, effective cutoff wavelength of the LP11mode, and the spot-size of the LP01mode, are clarified.