The Simulation And Optimization Of Sub-wavelength Composite Micro/nano-structure Optical-diodes

All-optical diodes are the most basic components in the application of integrated complex photonic circuits.Micro-nanostructured all-optical-diodes can meet the requirements of integration,miniaturization,low energy consumption,high speed and so on.It plays an important role in the development of optical computers and photonic circuits.In this paper,the principle that surface isophernions will cause abnormal transmission is used to design and optimize the structure of all-optical-diodes,so that the performance of all-optical-diodes can be optimized by one-way transmission.The surface isotherm is a common resonance produced by the free electrons on the surface of the micro-nano structure metal due to the excitation of the photon.It is a kind of common resonance along the surface of the metal rather than along the metal.An internal electromagnetic wave.When a plane incident light wave hits the surface of a metal with a subwavelength structure,the photons of the incident light wave will oscillate with the free electrons on the metal surface of the subwavelength structure and form a "local" electromagnetic wave coupled with each other.In this paper,all-optical-diodes are designed by adjusting the subwavelength complex microstructures to control the propagation law of surface isopherons and physical properties.In this paper,a three-dimensional hole-slot composite structure of all-optical-diodes is designed,and the structure is systematically designed and optimized.The contents of the work and the findings of the study are as follows:Firstly,according to the basic principle of micro and nano 3D all-optical-diode structure,Comsol software is selected to build the model of the three-dimensional hole slot structure.According to the known literature,the parameters are set up,and the simulation calculation is carried out.The results are compared with the known literature.Adjust,and finally verify the correctness of the model.It is concluded that the transmittance of single-hole and single-slot structure is about 1.69 times higher than that of single-hole without slot structure,and the far-field transmission is greatly enhanced.Secondly,on the basis of single hole and single slot,because of the principle that the surface isophosphate is most effective under symmetrical structure,the model of single hole symmetric groove is designed,and the data diagram of the relation between transmission and slot distance and the electric field mode diagram of single hole and double slot are obtained by calculation and simulation.Analysis and comparison provide data for the design of all-optical-diodes.According to the transmission spectrum of the distance between the single groove and the circular hole in the three-dimensional microporous single-slot structure,the normalized transmissivity changes periodically with the change of the groove position,and the peak value of the transmittance decreases with the distance d.But the transmittance valley value is basically stable.Two-slot symmetric structure is more exciting than single-slot structure.SPPs have a greater impact on transmission.The maximum transmission intensity ofsingle hole and double channel is about 1.69 times and 2.45 times respectively.Finally,the optimized all-optical-diode is designed.According to the data in front,the optimum position of the groove is determined,the model is established,and the different groove logarithms are simulated,and the transmittance and extinction ratio are obtained.The optimum groove logarithm and position are 4 pairs of grooves etched on the upper surface,and the structure of one pair of grooves on the lower surface can maximize the unidirectional transmission with the maximum transmittance of 5.83 times and the extinction ratio of 11 d B.The corresponding positions are:L₁=352nm,L₂=1200nm,L₃=2050nm,L₄=2920nm A pair of grooves are etched on the lower surface and are located in the same position.L₁'=1000nm.