PBG properties of three-component 2D photonic crystals

TL;DR

This paper theoretically investigates how adding a third component as an intermediate layer affects the photonic band structure and density-of-states in 2D photonic crystals, with implications for macroporous silicon.

Contribution

It introduces a model for 2D photonic crystals with a third interlayer and analyzes its impact on band gaps and surface oxide effects using the plane wave method.

Findings

Interlayer properties significantly shift band gap edges.

Surface oxide layers influence the optical properties of photonic crystals.

The model helps understand the optical behavior of macroporous silicon.

Abstract

In this paper we analyze theoretically how the introduction of the third component into the two-dimensional photonic crystal influences the photonic band structure and the density-of-states of the system. We consider the periodic array of cylindrical air rods in a dielectric, and the third medium is introduced as a ring-shaped intermediate layer between the air pores and the dielectric background. Using the plane wave method, we have obtained the band structures for the 2D triangular lattice photonic crystals. The dependencies of TE and TM band gaps' widths and gaps' edges position on the interlayer dielectric constant and interlayer thickness were analyzed. In the framework of this approach, we have estimated the influence of the surface oxide layer on the band structure of macroporous silicon. We observed the shift of the gaps' edges to the higher or lower frequencies, depending on the interlayer thickness and dielectric constant. We have shown that the existence of a native oxide surface layer should be taken into consideration to understand the optical properties of 2D photonic crystals, particularly in macroporous silicon structures.