Study On Voltage-Controlled Unidirectional Reflectionless Properties In Surface Plasmonic Waveguide

With the rapid development of integrated circuit and integrated optical technology,people look forward to information transmission,high efficiency and storage space.This is bound to require the future devices to develop in the direction of ultra fast,efficient and integrated.It is well known that the size of a photonic device is usually larger than the wavelength under the restriction of the optical diffraction limit.Thus,the rapid development of integrated optical technology is inevitably hindered.Therefore,new mechanisms and technologies are urgently needed to break through the diffraction limitation to realize nano-integrated photonic devices.Surface plasmon is a kind of electromagnetic wave caused by the interaction between light and electrons on metal surface.Its electromagnetic field has strong surface binding to break through the diffraction limitation.This special optical property is expected to be the basis of nano photon devices and integrated circuits.In this thesis,the controllable unidirectional reflectionless phenomenon is studied by using the system of nano resonators side/end coupling the surface plasmonic waveguide.The research contents are as follows:The controllable unidirectional reflectionless phenomenon is investigated by adjusting the applied external voltage in a system composed of two nano resonators side coupled surface plasmonic waveguide.The numerical simulation results show that the controllable unidirectional reflectionless phenomenon can be realized by adjusting the external voltage properly.Through the analysis of the scattering characteristics of the system,it is found that the numerical simulation results are completely consistent with the transmission matrix theory,which further confirms the possibility of unidirectional reflectionless phenomenon.Moreover,the effects of the distance between the surface plasmonic waveguide and resonator,the phase between the two resonators,the size of the resonator and the voltage on the unidirectional reflectionlessness are discussed.Under the condition of external voltage,the dual-band unidirectional reflectionless phenomenon is discussed in the system consisting of two ring resonators end-coupled with surface plasmonic waveguide.Through numerical simulation,it is found that the voltage controllable dual-band unidirectional reflectionless phenomenon can also be realized in the two ring resonators system under appropriate external voltage,and its scattering characteristics also conform to the coupled mode theory,thus further confirming the universality of the dual-band unidirectional reflectionless phenomenon.In addition,the effects of the external voltage and distance between the two ring resonators on the dual-band unidirectional reflectionless are studied in the two ring resonators system..In short,in this paper,we not only observed controllable unidirectional reflectionlessness but also confirmed its universality in the nano resonator side / end coupled surface plasmonic waveguide system.These researches will provide reliable physical model and theoretical basis for the application for surface plasmon switches,sensors,nano integrated circuits and other nano materials.