Simultaneous occurrence and compensating effects of multi‐type disorder in two‐dimensional photonic structures

Abstract

Abstract Finite‐difference time‐domain (FDTD) simulations of the transmission spectra of planar small‐footprint photonic components with up to four types of morphological disorder as a materials parameter are performed with the aim to identify the individual contributions of the type of disorder to the spectral features. We concentrate on optical components that have a small footprint, that is, their extensions in two dimensions are roughly one order of magnitude higher than the wavelength. They are modeled by a regular pattern of cylinders in a 7 × 10 square lattice, modified by the introduction of a disorder parameter varying either presence, radius, position, distance, or dielectric properties of the cylinders and the surrounding medium. Although the observation that an increasing amount of disorder results in a decreasing transmission intensity of an optical component is well known, quantitative studies of the particular spectral changes and a clear correlation especially with multiple types and amounts of disorder are rare. From these findings, we propose a model component that can incur a compensation of disorder‐induced spectral effects of geometric type with such effects of dielectric type. Our work shows that several types of disorder as well as the mixing two types of disorder can be used for an intentional adaptation of the spectral transmission characteristics and may be considered in the design of small‐footprint photonic components such as scatterers, diffusers, and waveguides.

Keywords

• dielectric interfaces
• disorder
• nanophotonics
• nanorods
• photonic crystals
• FDTD simulations