Research On Propagation Characteristics Of Index-guiding Terahertz Photonic Crystal Fibers By The Finite Element Method

The terahertz (THZ) region that lies between the millimeter and infrared region in the electromagnetic spectrum, with frequencies ranging from 0.1 THZ to 10 THZ. It is a transitional region from Photonics Technology to Electronics Technology or from macro to micro. They have very important scientific and application values because of their unusual region and various characteristic parameters. To date, progress in THz spectroscopy has been enormous. How to guide THz wave over long distance with low dispersion and low absorption coefficient still remains a challenge in this intermediate spectral region.The Photonic crystal fiber(the brief name PCF) which distinguished from the traditional optic fiber has the characteristics of the single endless mold to deliver, the adjustment of dispersion, the high double refraction and low loss and so on. So it has become a popular topic at home and abroad currently, In addition for the sake of analyzing and studying the optic characteristics of the Photonic crystal fiber in transfer, the people developed many analysis methods in theory, such as the Finite Difference Time Domain, the Finite Element Method, the Effective Index Model and so on. In these methods, the Finite Element Method has been a useful tool for analyzing the Photonic crystal fiber for that it suitable for any irregularly shaped, and has a highly accuracy results. These peculiar properties of the PCF have provide a method for designing a low loss terahertz photonic crystal fiberThe effective refractive index, effective mode area, dispersion and loss of total internal reflection terahertz photonic crystal fiber are investigated by finite element method (FEM) in this article. The effect of the distance between holes, the air filling factor on the propagation characteristics of total internal reflection terahertz photonic crystal fiber is discussed.