Research On The Two-Dimensional Photonic Crystals Slab Band Gap Properity

Phoxonic crystals are a novel artificially compounded microstructured materials with a periodic structure that possess both phononic and photonic band gaps and local modes.Among these physical properties,many of them are preferred to those of natural materials because of their band gap properties.Consequently,taking full advantage of this property allows the construction of a series of superior platforms for the control of electromagnetic and elastic waves,and it offers potential applications in the field of acousto-optical functional devices.The two-dimensional slab structure is a commonly used structural format and has been widely used in various mechanical engineering,so the research on the two-dimensional slabs phoxonic crystal band gaps has important application value.In this paper,the plane wave expansion method and the finite element method are used to calculate and analyze the band structure and acoustic and optic defect modes of two-dimensional phoxonic crystals slab.The main contents include the following:1.Firstly,the concept and characteristics of phonon crystals and their applications are introduced,then the theoretical and numerical calculation methods for calculating the band structure are presented,and the basic equations for regulating phoxonic crystals are described.2.Secondly,the band structure of the two-dimensional slab phoxonic crystal is simulated by using the plane wave expansion method and the finite element method,and various structural parameters affecting the band gap of the two-dimensional slab phoxonic crystals are analyzed.The structural parameters mainly including the lattice type of the two-dimensional slab phoxonic crystals,the shape of the scatterer,the size of the scatterer radius,and the thickness of the slab.3.Finally,the local characteristics of two types of defects in two-dimensional phoxonic crystals slab of two types of lattices were calculated by using the finite element method.Among them,we design point defects based on cross model and L3 model of square lattice,line defects based on linear and folded type of square lattice,and point defects based on L1 and L3 model of triangular lattice,and line defects based on linear and Y model of triangular lattice.Through the simulation calculations,it is found that when electromagnetic and elastic waves propagate in the phoxonic crystal,in the band gap frequency range,the defects will be localized to form localized modes within the defects,resonant cavities in point defects,and waveguide structures in line defects.