Interdependence of a waveguide and material dispersion

Theoretical work on dispersion in single-mode fibers sometimes uses the assumption that waveguide dispersion and material dispersion are separate effects that contribute additively to the total amount of dispersion. Using Gloge's LP-mode approximation the present paper computes the dispersion of the LP01 (HE11) mode by solving an eigenvalue equation taking into account dispersion of core and cladding materials. It is found that the assumption of additivity of material and waveguide dispersion is not quite correct; however, this has little influence on the overall dispersion of the LP01 mode.