Performance study of exponential varying refractive index planar slab optical waveguides

We study the mode cut-off condition as well as mode field structure of an exponential varying refractive index planar slab waveguide structure. The eigen-value equation has been derived by matrix method for the allowed waveguide structure by using Maxwell´s equation. The dispersion behavior has been predicted for the known case. The performance is well compared with the normal step index slab waveguide. It is known that the fundamental mode field shape is Gaussian for the case of planar slab step index optical waveguide, but it may not be Gaussian for the exponential varying refractive index slab waveguide. The shape of fundamental mode field profile is predicted for the specific case. Further group velocity dispersion as well as waveguide dispersion can also study from the outcome of these results. The optimization of the leaky waveguide structure has been further done, while varying the refractive index profile design parameters. The results are found satisfactorily. This study will be useful for the deployment of low loss WDM optical fiber link.