Dispersion characteristics of optical planar DFB guiding structures for optical communication

A rigorous modal approach based on the transmission-line description has de veloped to explore effectively the filtering characteristics of planar opti cal DFB guiding structures. Using the modal transmission-line theory, the l eakage and filtering characteristics of metal-strip gratings and dielectric gratings with gain or loss are first evaluated in details at the first- an d third-order Bragg regimes. It can thus serve as a powerful template for c omputational algorithms to determine systematically and rigorously the opti cal effects of multilayered periodic guiding structures, which are not read ily obtained by other methods.