A polynomial model of transmission and reflection of electromagnetic monochromatic plane waves in lossless, non-magnetic multilayer thin films subjected to an external transverse voltage

Abstract

A polynomial approach is adopted to simulate the optical-electrical response of a multilayer thin film subjected to an applied transverse voltage. Each layer in the thin film is modelled by a propagation matrix, while the coupling between any two adjacent layers at an interface is modelled by an interface matrix. Each layer in the multilayer thin film in the present approach is treated as a capacitor coupled to the next so that the multilayer film is modelled as an effective capacitor which is constructed by a series of coupled capacitors. The electric charges accumulated at the interface between adjacent ‘capacitors’ can be modulated by the transverse voltage. The model is constructed to describe only lossless and nonmagnetic materials. The reflection and transmission of multilayer MgO/CaF2 thin films with a selected number of layers and structure, subjected to a tunable transverse potential, are simulated with a home-grown code implementing the model. The numerical results indicate that non-trivial optical responses can be conveniently predicted with the code, providing a handy simulator for designing and optimizing desired optical functionality of an arbitrary lossless multilayer thin film by tuning the transverse potential and the geometrical and electrical parameter of the structure.