Analysis of point and linear defects inside photonic crystals with square and hexagonal lattices for communication applications

In the current study, we were theoretically able to determine the main difference between the point defect and linear defect of both square and hexagonal photonic lattices. For the point defect, the mode is trapped No matter where in the band structure its frequency falls. The mode of the linear defect is localized to one-direction propagation along with the defect, functioning as a propagation channel rather than as an area-trapping light source. When creating a point defect inside a bandgap, the electric field amplitude is broad and concentrated around the defect region and decays quickly as we move away from the site of the defect. While creating a line defect inside the bandgap, the amplitude of the electric field will continue to propagate in one direction to the end of the path of the line defect within the photonic crystal bandgap. Photonic integrated circuits based on photonic crystals are very important in the improvement of optical communication.