Surface Plasmon-induced Transparency And Realization Of Second Harmonic Conversion Research

Surface plasmon is a kind of electromagnetic oscillation mode formed by the interaction between free electrons on the metal surface and incident photons satisfying certain conditions.In general,when the frequency of the incident light is equal to electrons,surface plasmon resonance will occur at the metal-medium interface.When the size of the metal particles is much smaller than the wavelength of incident light,there will be oscillation around the metal particle,forming local surface plasmon resonance.The classical diffraction limit can be overcome by surface plasmon,which provides a new way to manipulate and control light on the nanometer scale.Many effects such as electromagnetically induced transparency,perfect absorption and sensing can be realized based on surface plasmon.At the same time,surface plasmon also has many applications in enhancing the nonlinear conversion,surface plasmon metamaterials and all dielectric metamaterials can greatly enhance the nonlinear conversion efficiency.Surface plasmon is widely used in optoelectronic integration,optical sensor parts,second harmonic and other fields,and has broad application prospects in information,energy and other fields.Based on the surface plasmon theory and the second harmonic nonlinear optical theory,combined with the theoretical simulation of the finite element method of COMSOL software,we make the research of plasmon induced transparency and the enhancement of the second harmonic conversion efficiency,the main contents of this paper are as follows:(1)Summarizing the research background,research status and application prospects of surface plasmon briefly.(2)Based on the theory of electromagnetic field,the surface plasmon,the relation of dispersion and its excitation mode are introduced.At the same time,the finite difference time domain method,the strict coupled wave method and the finite element method are introduced.The finite element method used in this study is emphasized.(3)Firstly,a near infrared broadband local plasmon induced transparency metamaterial is designed.The transmittance is more than 80%,and the transmission bandwidth is up to 250 nm.By changing the geometrical parameters of the metamaterial,the transmission bandwidth can be adjusted or the transmittance can be controlled.Secondly,a kind of rectangular ring structure with rectangular strip waveguide is designed,which can achieve high transmittance at specific wavelength and plasmon induced transparency effect.The influence of the parameters of the rectangular strip on the transmission is studied.When the parameters of the rectangular strip are changed,the position of the transmission peak will shift.The influence rules of the parameters are summarized.(4)We introduce the development of nonlinear optics and the background of the surface plasmon in enhancing the second harmonic conversion efficiency.A structure composed of metal and nonlinear medium is designed.After parameters optimization,the efficiency of second harmonic conversion can be enhanced.The results have certain application value.