Research On The Metal Surface Plasmonic Ring Cavity's Resonance Mode

In modern society, communication systems dealing with vast amounts of data at ever increasing speed started to progressively stronger experience the fundamental limitations imposed on the existing electronic and optical technologies.Specifically, nm-sized electronic (metallic) circuits are inherently slow due to RC-delay times, whereas optical (dielectric) circuits having enormous information capacities are essentiallyμm-sized due to diffraction effects. Surface plasmons (SPs) is the electromagnetic modes supported by metal-dielectric interfaces. These modes, in which optical fields are coupled to electron oscillations, are characterized by the wavelength that is always shorter than the wavelength in the dielectric, exhibiting thereby subwavelength confinement. Optical microresonators have demonstrated great promise as fundamental building blocks for a variety of applications in photonics. The ring resonator based on metal-insulator-metal waveguide with its small size, compact, has great potential to become a new generation of integrated nano-optical basic components. The resonance mode of the ring resonator based on the surface plasmon MIM waveguide has been studied in this thesis. Numerical simulation method of finite difference time domain has been used to study the metal ring resonator's resonance mode. The major research work of this thesis are summarized as follows:(1) First the author studied the characteristics of the resonance mode of the FDEKF which was based on square ring cavity by the method of numerical simulation. The author also compared the resonance mode of the L-type ring resonator and the curved corner square ring resonator and found that their resonance lines were very similar, which indicated that the ring resonator's resonance mode associated with the overall structure.(2) By introducing the curved corner structure, the light reflections produced by the right-angle can be avoided and the standing wave mode can also be eliminated, which is good for the transportation of the energy. Besides that, the arc corner structure is in low technology requirement during the process of nanolithography. This conclusion has certain significance on the crafts making.(3) From the study on the ring resonator's resonance mode, We found that the resonance peak of the ring cavity was relatively sharp and the filtering was precise and accurate. This was a big advantage of the ring cavity. Then we proposed a runway-shaped ring cavity structure in order to improve the coupling efficiency, which combined the advantages of the square cavity and the ring cavity and achieved a better filtering effect.(4)We discussed the influence of different ring resonator's radius and width on the resonance mode. Because the ring resonator waveguide structure is different from the straight waveguide, thus the structure of the propagation mode of the surface wave plasma in it is different, which indicates the propagation mode of the surface plasmon in the MIM waveguide structure mainly depends on the waveguide structure.