Design and analysis of a position chirped metamaterial photonic crystal array for confinement of light pulses

Abstract

In a photonic crystal (PC) array, a line defect (removal of a periodic structure) and position up-chirping (gradually decreasing lattice constant) are familiar terms to introduce light confinement and propagation due to the photonic bandgap (PBG). In this paper, we have proposed a new model for light confinement using a line defect position chirped PC array with metamaterial as a dielectric material. For comparison, we have designed and simulated for both line defect positions chirped and none position chirped PC array using normal material (refractive index +3.927) dielectric material and metamaterial (refractive index −3.927). We have used metamaterial due to the compensation of light dispersion and leakage effect because the negative refractive index makes the wave vector direction precisely opposite to the positive refractive index material. We have implemented the metamaterial positioned chirped PC array with sharp 90° bending and shown the light confinement and propagation for that structure. To support our proposed model, we have calculated the band diagram of both positive refractive index and metamaterial unit cells and verified the quantum well existence in the band diagram of metamaterial unit cell. Based on the quantum well effect, the confinement of light in metamaterial line defect position chirped PC has been explained and presented with proper finite element method (FEM) simulations. From quantum mechanics, we can comprehend that confining wave particles at the atomic level is extremely challenging because of the evanescent nature of the light wave. The novelty of this paper is that we have managed to confine the propagating of light waves by using the quantum well existence in the metamaterial dielectric for a line defect position chirped PC structure, and to the best of our knowledge, we are probably the first to introduce light confinement using a metamaterial chirped PC structure with proper FEM simulation.