Mode dispersion, material dispersion and profile dispersion in graded-index single-mode fibres

A study of single-mode fibres shows that in the normal operating region the cladding has as much effect on the propagation constant as does the core. A detailed analysis shows that the complex expression for pulse dispersion can be arranged in three groups of terms which may be defined as composite material dispersion, waveguide dispersion and composite profile dispersion. The analysis has been applied to a fibre for which the material dispersion parameters are accurately known and it is found that zero total dispersion can be obtained at a wavelength which depends on the profile and the core diameter but may be selected within a range roughly 1.3¿¿2 ¿¿m. However, there are severe requirements on the control of core diameter and profile.