Modal transmission-line theory of multilayered grating structures

Solutions to problems involving the scattering and guiding of waves by multilayered grating configurations can be phrased in rigorous modal terms. We show that such a modal solution can be represented by electrical transmission-line networks, which are generalized forms of simpler conventional circuits. This approach brings considerable physical insight into the grating diffraction process and facilitates the derivation of the fields everywhere. In particular, the transmission-line representation can serve as a template for computational algorithms that systematically evaluate dispersion properties, radiation effects, wave coupling and other characteristics that are not readily obtained by other methods. Examples illustrating the application of the present approach are given for waves guided by grating configurations encountered in optoelectronic devices.