Application Of Finite Difference Time Domain Method In Photon Diode

All-optical diode is the most basic photonic device in integrated optical circuits.To develop a modulated optical diode is of great significance for preparation of complex optical circuits in the near future.The main research content of this thesis is:The Maxwell equation is solved by the finite difference time domain(FDTD)method,and then the corresponding extraordinary transmission mechanism of the metallic silver under the nanostructure is simulated and investigated by the corresponding electromagnetic theory.And the surface plasmon polaritons(SPPs)is dynamically modulated to obtain the structure with the best extinction ratio.The surface plasmon polaritons(SPPs)is an electromagnetic pattern conducted along the metal surface,which is the electromagnetic wave generated by the mutual coupling of the free electrons and the incident light on the metal surface.It is a special electromagnetic wave that produces beyond the diffraction limit of conventional optics.There are more and more studies about the subject of extraordinary optical transmission(EOT)phenomenon based on surface plasmon polaritons.The rapid development of information technology and computer technology has led to the rise of computational electromagnetics and the rapid development.In the solution of electromagnetic field problem,FDTD method is a calculation of electromagnetism in a good calculation method with many very prominent advantages,such as direct processing in the time domain,wide range of uses,low computational cost,and low storage capacity.In this paper,FDTD method is used to study the effect of surface plasmon polarons on EOT phenomenon.By using the adjustment of the structural parameters,the control of the surface plasmon polarization is realized,and the structure design of the light beam unidirectional transmission is realized.The main work of this paper research methods are is as follows:1.The finite time do(?)ain difference(FDTD)algorithm is studied,and a dielectric sphere electromagnetic scattering graphical user interface(GUI)based on FDTD is written in this paper.2.The finite difference method is used to analyze the most simplist metal-silver single-slit structure,and a simple and optimal model for EOT is obtained.3.The single-slit-symmetrical double-groove structure of metallic silver is studied by using the best metal-silver single-slit structure as template.The effect of structural parameters on the unidirectional transmittance of the structure is analyzed,and the normalized transmittance of the subwavelength structure is maximized,and the single slit-symmetrical double groove structure with the maximum extinction ratio of 38dB is obtained.This structure is transmitted in the positive direction of the light is transmitted in the opposite direction 6310 times.This study provides a basic model for the study of complex structured photon diodes in the future.