Directional emission of the edge states from the photonic topological structure composed of two-dimensional honeycomb photonic crystals

Abstract

In this work, we investigate a two dimensional honeycomb photonic crystal (2D HPC) with 𝐶 symmetry point group, which is known to demonstrate a double Dirac cone at 𝑘 = 0 of the Brillion zone. Then we design two deformed PCs from the original one, by modifying the radius of the cylinders from the unit cell center in which the symmetry 𝐶 is reduced to the 𝐶 group and new structure exhibits the photonic topological edge states. Consequently, the topologically protected propagation of the edge states with back scattering-immune feature is observed along the interfaces of the two deformed PCs without any defects or including cavities or bend. Furthermore, the directional surface modes exit from the photonic topological insulators (PTIs) including various defects, is investigated. As well as, we explore the propagation and coupling of light through the coupled photonic topological insulators (CPTIs).

Design and Performance Analysis of Perovskites Unidimensional Photonic Crystal-Based Biosensors for Extracellular Vesicles Detection: A Numerical Investigation

“…Photonic crystals (PCs) are structures composed of alternating materials with different refractive indices leading to the manipulation of electromagnetic waves. These structures have unique properties, such as high reflectivity and wavelength selectivity in unidimensional photonic crystals (1D PCs) [1,2], directional emission, anisotropic behavior and guide modes of light in bidimensional photonic crystals (2D PCs) [3,4], and complete photonic bandgap formation, photonic quasicrystal and tunability in three-dimensional photonic crystals (3D PCs) [5][6][7]. In addition to these properties, PCs can slow light propagation [8] and enhanced light-matter interactions [9,10].…”