Study On Numerical Characteristics Of Plasma And Its Photonic Prystals Based On Symplectic Multi-Resolution Time-Domain Method

The dispersion and dissipation characteristics of plasma media,which are widely used in communication,stealth,medical treatment and so on.Plasma photonic crystals have unique properties due to the physical properties of plasma,in addition to the characteristics of ordinary photonic crystals.The two outstanding characteristics of electromagnetic waves propagating in plasma photonic crystals are photonic band gap band and photonic localization,which make it have important industrial application prospects in photonic crystal waveguides,filters,antennas and other devices.As we all know,the finite-difference time-domain(FDTD)method is the most classical and mature numerical simulation method for electromagnetic calculation,but it is susceptible to the limitations of stability and numerical dispersion characteristics,which leads to the accuracy and efficiency of this method in practical simulation calculations.With the substantial improvement of computer performance,many numerical methods have emerged for the processing of complex data.Recently,the emerging symplectic multi-resolution time-domain(S-MRTD)method can make up for the disadvantages of traditional FDTD method.In response to this phenomenon,the S-MRTD method is first introduced to the numerical simulation calculation of plasma and its photonic crystals.The innovation of this paper mainly includes the following:(1)The theoretical framework of S-MRTD method based on the perfectly matched layer(PML)developed by split-field technology is preliminarily constructed.The stability and numerical dispersion characteristics of the free space S-MRTD method are analyzed deeply,and it is concluded that the S-MRTD method developed by three-stage three-order symplectic operators combined with Daubechies scale function has better stability and numerical accuracy.Through numerical simulation,the energy conservative characteristics and high accuracy of S-MRTD method are proved.(2)The Maxwell's equations containing the plasma media are written in the form of Hamilton system,and an efficient S-MRTD method solution for the plasma media is established.Two kinds of numerical discrete iterative formulas for unmagnetized andmagnetized plasma media are presented,and compared with the traditional FDTD method.The reflection and transmission coefficients of electromagnetic wave incident vertically into the plasma media are analyzed,and the performance advantages of S-MRTD method are verified from the perspective of calculating time and occupying memory.(3)The S-MRTD method solution based on the constructed plasma media is applied to the numerical simulation of the plasma photonic crystals(PPC).First,the photonic band gap(PBG)periodic properties of one-dimensional PPC and the local defect mode of PPC with a single defect layer are discussed.Then,the defect mode character of multi-defect layer is studied.Finally,the transmission characteristics of two ternary structure PPC models are analyzed.The feasibility of S-MRTD method to simulate PPC is comprehensively verified.