The Optical Control Of Surface Plasmon Polaritons Resonator

Surface Plasmon Polaritons(SPPs)are a kind of electromagnetic field modes,the electrons on metal surfaces propagate along the surface due to the external electromagnetic fields.It can not only enhance the local light,but also control the spread of light in the sub-wavelength scale.Because of its compact structure and its superiority in light transmission and modulation,it has become an attractive research area in nanophotonics.A series of surface plasmon waveguide structures such as metal strips,nanowires,gap structure,etc.have been used in the nano-optical circuit.Among them,Metal-Insulator-Metal Structure(MIM)has been the focus of recent research due to its strong binding effect on light and good propagation distance.A variety of MIM-based devices,such as couplers,beam splitters,Mach-Zehnder interferometers,Y-type waveguides have been extensively studied.We will design and verify the all-optical switch using these advantages of SPPs-based MIM waveguide.A MIM waveguide based on SPPs is designed in our work.Its uniqueness lies in the double-layer metal layer,which compose of silver and iridium,the bimetallic layer is placed on the top of the structure.The structure is heated by the resonance of the light in the cavity,beacuse of the large difference between the thermal expansion coefficients of the two materials,the heated structure will be deformed,resulting in changes of the cavity volume,eventually the transmission spectra of the structure will occur redshift phenomenon.In this paper,COMSOL is used to simulate the whole physical process of the optical devices.The structural parameters of the all-optical switch are determined.The influence of the wavelength,incident power and heating time of the beam on the temperature of the whole structure is discussed.The influence of different temperatures on different wavelengths is verified.Since the temperature caused by the light beam rise slowly,we apply the pressure to the top of the structure directly,and studying the effect of pressure-induced deformation on the cavity structure,which provides a reference for practical application.