PHOTONIC CRYSTALS WITH DIRAC CONE DEGENERACY

Abstract

In the last decade, intensive investigations have been carried out on photonic crystals because of their remarkable features. One of these features is the Dirac cone of the photonic crystal band structure, where two conical bands are touching at a single point. Our study focuses on photonic crystals with Dirac cone degeneracy at different high symmetry points – Γ point and K point. The Photonic crystal with Γ point Dirac cone can also be seen as zero-refractive index material, where light waves propagate with infinite phase velocity. This thesis especially investigated the low-loss properties and waveguide application of zero-index material. Stacking and twisted two layers of photonic crystal sheet with K point Dirac cone introduce a special phenomenon of Dirac cones hybridization. The results of Dirac cones hybridization at a certain small angle are ultra-flat photonic bands and exhibit extreme slow light behavior.