Two-dimensional Triangular Lattice Photonic Crystal And Waveguide Transmission Characteristics

In this paper,we introduce the general characters and applications of photonic crystal systematically,then,we derive FDTD method in detail.The main work is using FDTD method study the transmission characteristics of 2-Dtriangular lattice photonic crystal under TE mode, and its specific contents as follows:The transmission characteristics of 2-Dtriangular photonic crystal of three elements which constructed with layer medium rods/bottom medium and air rods/bottom medium,the result shows that:Photonic band gap(PBG) can be achieved from low to high frequency,which is much larger than a single photonic crystal in this combination structure,so as to prohibited the electromagnetic wave in a wide frequency range.In order to learn regular patterns of PBG,we continue to investigate study the impact induced by structure parameters,it shows that the external radius of layer medium rods have influence to the width of band gap,while the internal radius and dielectric constant,dielectric constant of the layer have influence to defect mode in the band gap;Defects caused by the dielectric constant change more significantly than medium rods;dielectric constant of internal rods affect defect in high frequency unlike that caused by the layer's dielectric constant.The results are meaningful on designing of 2-D photonic crystal devices such as optics filter and switch.Filter characteristics of 2-D photonic crystal line waveguide of the ellipse air columns are examined,results show that:Air columns azimuth from 0-90 degrees changes;some frequency defect mole appears;Rods have three totating ways,which are rotating in the same direction, rotating mirror symmetry and two rows which near the line defect waveguide rotating.If rods rotate in different ways,defect-mode frequency range is different,and center frequency of flaw mold to high frequency mobile as air columns azimuth become large.Therefore,it can achieve to control optical wave through rotating the angle of rods.The transmission characteristics of 2-Dtriangular photonic crystal waveguide with a dot-defect.The result shows the same frequency components light waves is "introduced" to the micro-cavity;Through changing the air column azimuth or the size around the microcavity,it may realize the resonance frequency adjustment.