Research Of The Transmission Characteristics Of The Resonator Based On Surface Plasmon Polaritons

Surface plasmon polaritons (SPP) are electromagnetic waves propagating along the metal-dielectric interface, and have the ability to confine the electromagnetic energy to a small region much lower than the diffraction limit. The resonator based on SPP has the properties of SPP and the resonator, the waves in SPP mode are trapped in the small size of the resonator cavity, and transmitting.back and forth under the action of a variety of feedback mechanisms in the cavity. Otherwise, the transmission spectrum is one of the most straightforward way to characterize the change of the energy of SPP.In this paper, we have introduced the theory and transmission characteristics of the Metal-Insulator-Metal (MIM) waveguide and the resonator based on the generation mechanism and the transmission characteristics about SPP, and had a lot of investigation about filter, WDM, switch and splitter composed by MIM waveguide and the ring resonator, disk or square ring resonator and so on. Combining the theory and numerical simulations, we have analyzed the transmission characteristics of the ring, the disk and the square resonator, and found that the transmission from these structures is simple and smooth, so they may be used as band-pass or band-stop filters, splitters and WDM. In addition, the transmission has showed that we can change the property by changing the size of the structure, the relative position of the waveguide and resonator, introducing multiple resonator to constitute a multi-channels, changing the dielectric embedded in the structure as well as the introduction of structural defects to break the original resonance.So, we have presented a new structure based on SPP resonator as a plasmonic splitter. This splitter consists of two parallel waveguides and two resonators. One resonator is a ring tangentially connected with the two waveguides, and the other resonator is a semi-ring directly connected to the lower waveguide. The finite-difference time-domain (FDTD) method is used to numerically analyze the transmittance spectra of the splitter. We have discovery that the transmittance between the wavelength of1310nm and1550nm can be used as a beam splitter in optical communication system. At the same time, we numerically simulate by changing the radius of the ring, the distance between the ring and the semi-ring resonator and the refractive index of the medium dielectric, the results show that the increasing radius and permittivity leads a red shift of the resonant wavelength. Thus we can obtain the arbitrary power splitting ratio at optical fiber communication waveband by adjusting R and n. Moreover, the transmission has shown that L have an influence on the property, when its value equals half of the circumference of ring resonator, it will make the splitting ratio over200. While the transmission won’t change if w is set to so large that there is no direct coupling between the ring and semi-ring resonator. The maximum power splitting ratio occurs at λ=1355nm and λ=1553nm which are very close to the telecommunication wavelength used in optical fiber. The maximum ratio is over200and makes the splitter to be a beam splitter. To our knowledge, this is the first designed surface plasmon polaritons (SPPs) splitter which utilize both the communication wavelengths around1310nm and1550nm. We will achieve a tunable splitter with high splitting ratio working on the communication waveband, which can be easily adjusted by the size of the resonator or by the dielectric embedded in the structure.In conclusion, we have explored the properties of the resonator and proposed a new nano-structure as a splitter, based on the theory of the surface plasmon polaritons for the purpose of researching the transmission characteristics of the resonator, which will provide a reference for the study of micro-photonics devices.