The Research Of Photonic Band Gap Of Two-Dimensional Compound Photonic Crystal And The Transmission Characteristics Of V-waveguide

Based on the related summarizes and analyzes of the study of photonic crystals, this paper further explore the nature of photonic crystals and the laws of photonic crystals. Using the superposition of the square lattice photonic crystal structure and the grid structure, we design the structure of the photonic duplex crystal lattice. By adjusting the width of the square media columns of the square lattice structure and the width of the grid structure, and changing the dielectric constant of the double lattice structure, thereby it can reduce the symmetry of the photonic crystal. Using the plane wave expansion method, there study the variation of two-dimensional compound photonic crystals and the complete band gap in theory. The study shows that in the square lattice structure, when only existing a square dielectric cylinder and adjusting its width, so that there is only the band gap of TE mode; Only existing the periodic grid structure, there is only TM mode band in the case of the appropriate width of the grid. In the case of compound lattice structure, adjusting the width of media column and grid that can be obtained the bigger width of complete band gap whose width is 0.0417ωe(ωe is center frequency). By changing the dielectric constant of double lattice structure, its complete band gap showed some variation.In order to study transmission characteristics of light in the frequency range of the band gap of photonic crystal, we continue to explore theⅤ-type waveguide of photonic crystal. According to the plane wave expansion method to calculate the band gap of triangular lattice of two-dimensional photonic crystal, it is optimized byⅤ-type waveguide structure. The study shows that by appropriate dielectric constant and the appropriate radius of dielectric cylinder in theⅤ-type waveguide, it can get that the light of TE mode can spread along theⅤ-type defects in the frequency range of their band gap. Under the corresponding conditions, theⅤ-type waveguide of TM mode does not exist the band gap, the light of TM mode is not spread along the defect ofⅤ-type waveguide. By changing the dielectric constant and the radius of dielectric column, the corresponding band also will be changed and shows the corresponding variation. Because the band frequency range of light waves can be spread along the defect ofⅤ-type waveguide in the band gap, the other band frequency ranges of light waves will be attenuated rapidly in the waveguide. So these features provide a theoretical basis for making the photonic crystal waveguide of a particular frequency band.