Research On The Propagation Characteristics Of Two-dimensional Metal Photonic Crystals Based On FSE

With the development of science and technology,electronic technology and microelectronic technology have entered a bottleneck period academically.Photonic crystal is a kind of intraocular crystal material which can control its internal radiation mode and has special response to external excitation field.One medium of great interest to photonics researchers is metals,the surface of which guides light in a surface plasma mode and thus has the potential to provide the basis for sub-wavelength scale nano-photonic devices.Although metal surfaces produce surface plasmons,they also exhibit significant optical absorption and loss.In this paper,based on Fourier series expansion method,five two-dimensional metal photonic crystals with cylindrical periodic chain structure,three two-dimensional metal photonic crystals with layered cylindrical periodic chain structure and a single two-dimensional metal photonic crystal composed of near-zero materials and metals are studied.The main research work is as follows:Firstly,the propagation characteristics of the periodic chain structure of single-layer gold and silver alloys are studied.Using two kinds of data and three methods,the complex propagation constants of the infinitesimally long sterling silver periodic chain structures in the range of 270-810 nm are studied,and the characteristics of the complex propagation constants are analyzed.Then,the complex propagation constants and field distribution characteristics of pure Au,Au:Ag(1:4),Au:Ag(1:2)and Au:Ag(2:1)periodic chain structures are studied.In this paper,it is found that the frequency range of the propagating state is lower than that of the pure silver periodic chain structure when the gold content is lower in the gold-silver alloy chain structure.By gradually increasing the proportion of a certain metal in the alloy,the propagation characteristics of the alloy photonic crystal are explored.Secondly,aiming at the propagation characteristics of the periodic chain structure of multilayer gold and silver alloy,the propagation characteristics of the periodic chain structure of two,four and eight layers metal cylinder are studied in turn.Compared with single-layer gold and silver alloy photonic crystals,the phenomenon of odd mode and even mode occurs in all layers,which can be used for multi-mode transmission communication when the number of layers is small.When the number of layers is more,there are a large number of odd mode and even mode,and the measured frequency segment is attenuation and cutoff state,you can make mirrors,filters,etc.In addition,it is found that when the volume of scattering unit is reduced,the number of odd mode and even mode is reduced,and all the measured frequency segments show better propagation characteristics,which can be used as guide mode devices,and can also be used for multi-mode transmission communication.Finally,we continue to study monolayer two-dimensional metal photonic crystals composed of near-zero materials and metals.Normally,the cutoff frequency range of metal photonic crystals increases with the increase of the volume fraction of the metal cylinder.However,our results show that the cutoff frequency of photonic crystals composed of metal cylinders and nearzero material background is independent of the volume fraction.In addition,it is found that with the increase of volume fraction,the range of cutoff frequency at high frequency becomes wider and wider.Using this characteristic,this paper studies to select electromagnetic wave of specific wavelength segment from intermediate frequency segment by increasing or subtracting R/a ratio.In addition,in this paper,40 photonic crystals composed of metal cylinders and near-zero materials are taken as the research object to study the plane guided wave capability of the finite array at a specific wavelength.