Research On The Anomalous Propagation Phenomena Of Electromagnetic Waves In Photonic Crystals With Square Rods

Photonic crystals (PCs) is an artificial medium whose refractive index is periodically arranged. Due to its controllable dispersion characteristics, electronic waves present many abnormal transmission phenomena such as negative refraction and flat slab imaging, self-collimating effect and superprism effect etc in this material. These abnormal phenomena present adequately the ability to control action of the photons, and the research on these abnormal phenomena has very important scientific significance and application value for development of photon device based on PCs.The thesis studies mostly the rule that primitive cell's fill material regulate and control the equipfrequency contour, and mechanism that produce abnormal refractive and reflect totally phenomenon such as PCs that consist of Two-Dimension square dielectric rods idiographic. Then we explore the application for the design of optical function apparatus, and we get some production as follows:1. The propagation of electromagnetic waves is investigated in two-dimensional photonic crystals (PCs) which are formed by square dielectric rods. Total reflection and self-collimating phenomena has been found in the first partial band gap when the cut directions of interface is changed. When the interface of the photonic crystals is along the direction ofΓX, the incident beams are reflected totally because none of the eigen-modes in the PCs could be excited. If the interface turns toΓM, due to its flat EFCs the incident beams with different angles refract nearly in the same direction in the PCs, i.e. the self-collimating phenomena occurs.2. The fundamental that Guass beam realizes the expansion and constriction of beam in two-dimensional photonic crystals (PCs) which are formed by square dielectric rods arranged in a square lattice is investigated. The plane wave expansion method is used to calculate and analyze the photonic band structure as well as the equifrequency contours (EFCs) character of two-dimensional photonic crystals (PCs) which are formed by square dielectric rods. The effect of expansion and constriction of beam could be found in the given frequency when the cut directions of interface are changed. Then numerical simulations using the finite-difference time-domain (FDTD) method are performed to investigate the propagation properties of the Guass beam. When interface with different cut directions of PCs are used combined, we found that the capacity of constriction of beam could be regulated when the thickness of PCs is different.