Research On Resonance Characteristics And Modulation Of Nano-ring Resonator

Surface Plasmon Polaritons (SPPs), which are electromagnetic waves propagating along the metal-dielectric interface with an exponentially decaying field in both sides, have been considered as energy and information carriers to overcome the diffraction limit of light in conventional optics. In recent years, people pay close attention to SPPs based subwavelength optics. SPPs provide a new way for people to control the transmission of light in the nano-metal structure. Scientists design and investigate various new micro-nano photonic devices, which have broad application prospects in future optoelectronic integrated circuits and photonic computers, as well as optical excitation, data storage, microscopic technology and bio-photonics and other fields. Based on existing researches both home and abroad, in this thesis we study the basic physical properties of surface plasmon resonance of some nano-structured photonic devices using FDTD method. Some new phenomenons are found, and the possible application for optoelectronic integrated circuits has been discussed.Our main work is listed below:An filter which is based on side aperture-coupled square-ring resonator is proposed. The transmission characteristic of the SPP filter and the SP resonance mode is investigated in detail by using FDTD method. And some new structural regulatory factors are introduced. Results show that lifting of degeneracy exists in both even-modes and odd-modes for the regular side-coupled square-ring resonator. By introducing the aperture between the ring and bus waveguide, semi-integer resonance modes with high drop efficiency emerge in the optical transmission spectrum. Further simulation results show that semi-integer modes can be efficiently modified and linearly tuned by adjusting the parameters of the resonators such as side length of the ring, the width of the aperture and the medium inside the aperture. The simple band-stop SPP filter is very promising for high-density SPP waveguide integrations.Influence of metallic nano-wall on side coupled ring resonator is studied. We propose an new method which introduces a metallic nano-wall to the circular and square ring resonator at different positions. Interest modulation results were found to the transmission spectrum. Simulation results show: compared with ordinary side-coupled resonator, the introduced metallic nano-wall can selectively suppress one of the resonance mode and let the other pass. Hence, the metallic nano-wall can be treated as a optical switch. Through changing the position, we can manipulate which signal can be passed or prohibited. This device can be applied to high-density integrated photonic devices and photonic computer.