FDTD Analysis Of Plasma Photonic Crystals

Photonic Crystal is an artificial structure which has a periodic arrangement of dielectric or metallic materials. It is so-called"photon-semiconductor". In the past decade, it has become a new fast-developing research field due to its unique properties and many potential applications.Plasma photonic crystal (PPC) is a periodic array composed of alternating thin plasmas and dielectric materials (or vacuum). Characteristics of 1-D and 2-D plasma photonic crystal structures were studied in this article. Characteristics of one dimensional and two dimensional PPC structures with numerical simulations were researched. The band-gap characteristics of PPC structures with different geometries and parameters have been studied to obtain the intrinsic relationship of band-gaps, and the results would provide instructions for design PPC structures.Because of the complex of the structure of plasma photonic crystal, it is very hard to analyze a plasma photonic crystal in an explicit analytical method. We usually analyze plasma photonic crystal through numerical simulations. So, numerical method is one of the most important parts of this paper.The finite-difference time-domain (FDTD) technique receives growing attention in the area of electromagnetic simulation. It is based on a direct discretization of Maxwell's equations in the time domain. It can simulate electromagnetic field distributions in structures of arbitrary geometry. Another advantage of FDTD is that it provides a pulsed start field and Fourier transforming the response.The piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method for the simulation of plasma photonic crystal is used here. It's a new numerical method for the dispersive medium.For many applications of photonic crystals, it is essential to design structures with large band gaps. First, plasma photonic crystal has been investigated with FDTD methods and effects of permittivity have been obtained. The results show that band gaps appear easily with more change rate of permittivity. And the band gaps disappear when less changes of permittivity. Second the relationship between band gaps of the plasma photonic crystal and plasma parameters has been discussed. We find out the increasing of the plasma frequency arouse the obviously EBGs. Bandwidth is narrowed and the attenuation of the reflection coefficients is rising.To increase range of band gaps, kinds of structures have been invented, such as series structures, parallel structures. In this paper, a new definition is given which is called composite-plasma photonic crystal. It is made up of two kinds of plasma photonic crystal with different parameters. One kind of one-dimensional composite-plasma photonic crystal and one kind of two-dimensional composite- plasma photonic crystal are calculated. The result shows that the band gaps are obviously wider than that of both composite plasma photonic crystals. In conclusion, the work in the present thesis is devoted to numerical methods, designing new plasma photonic crystal structures of large photonic band-gap. Much progress has been obtained in both of the above-mentioned aspects.