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The enormous transmission capacity of the order of thousand of Gb/s offered by single mode fibers cannot be fully
utilized with the conventional step index fiber. However for these designs and the new ones to come a numerical
technique, which is fast and accurate, is required for calculating the dispersion. Most of the existing numerical
approaches are good enough for the calculation of propagation constant only, though some of them are not suited for
arbitrary refractive index profile. A powerful numerical technique, the quadratic finite element method [FEM] is used
for analyzing the modal characteristic of single mode optical fiber with arbitrary refractive index profile. The
simulated results when compared with earlier reported ones for step index profile, confirms the accuracy of the
proposed numerical technique. It is shown that multiple cladded fiber is better suited for Wideband Systems.
Dispersion flattened fibers have been proposed in the past with W - profile, but all such fiber designs have been
observed to be bend sensitive in the long wavelength window, as one has to operate very close to the cutoff of the
fundamental mode. A generalized refractive index profile has been used here, which is capable of generaing a variety
of earlier proposed profile. Computation shows that by properly optimizing the profile parameters, a wideband fiber
can be designed where the dispersion can be kept confined with in ± 1.0 ps/ km - nm over a wide entire wavelength
span from 1280 to 1550 nm ( 370 nm). The proposed fiber consists of Quadruply Cladded (QC) Profile and is
capable of transmitting high speed data ( > 1 Tb/s). The proposed design is expected to be relatively insensitive to
bending losses, as the field even at longer wavelength (1550 nm) is well guided within the QC fiber structure. The
wavelength span includes both the low loss transmission window near 1310 & 1550 nm. The results suggest an
excellent wideband optical waveguide for future WDM systems.
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