Designing a graded index depressed clad non-zero dispersion shifted optical fiber for wide band transmission system

Abstract

Non-zero dispersion shifted fibers (NZ-DSFs) find extensive use in wavelength division multiplexed (WDM) system as it reduces the non-linear effects like four-wave mixing (FWM) generation. A depressed clad graded index fiber with a central dip in the refractive index profile, as well as without dip, has been modeled to perform as an NZ-DSF using the spot size optimization technique. The performance characteristics of the proposed NZ-DSF have been studied by changing different fiber parameters; such as inner core radius ( a), relative refractive index differences ( Δ +), normalized end position of depressed clad ( C), depression parameter ( ρ), etc. for a given value of Petermann-2 spot size ( W ¯ ) . By suitably adjusting the fiber parameters, the effective core areas ( A eff) as simulated here are very large (∼80 μm 2) so that the effect of non-linearities upon them can be minimized. These NZ-DSFs have also been optimized for WDM transmission system. The dispersion slopes of the proposed fibers with and without dip have been estimated which are comparable with the reported results.