Minimum dispersion in a single-mode step-index optical fiber

The cancellation between material and waveguide dispersions for weakly guiding single-mode step-index fibers has been analyzed to predict the optimum wavelength lambda(0) for zero first-order dispersion and the residual second-order dispersion T. Greater accuracy in our numerical calculation of waveguide dispersion results in significant change in lambda(0) and T compared to the previous work by another investigator. The dependence of lambda(0) and T on the normalized frequency and relative index difference has also been improved and extended numerically. Physical origin of this dependence is discussed; it is considered to be due to different optical power distributions between core and width of the source.