Linearly combined optical structures based on SiON

Abstract

We investigate an optical structure that results from a linear combination of two periodic, multilayer dielectric functions of slightly different periodicities. By solving the corresponding Maxwell's equation, we show that such linearly combined optical structure supports a dense number of localized (slow) modes. For a practical implementation of the linear combination of the dielectric functions, we make use a silicon oxynitride (SiON) material platform where the refractive index of SiON can be tuned over a continuous range, by changing the percentage of oxygen. The proposed optical structure works, despite a system of low refractive index contrast, and can be effectively used to create efficient polychromatic slow light systems and devices.