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 λ0 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 λ0 and T compared to the previous work by another investigator. The dependence of λ0 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 cladding for different constituent wavelengths within the spectral width of the source. © 1979 Optical Society of America.