The Property Reaserch And Simulation Of The Precious Metal Waveguide And Nano Structure Based On The SPP

The integration and miniaturization of optical devices are the requirements of information technology development, but the diffraction limits of traditional dielectric waveguide constraint the integration intensity. Numbers of free electrons at the interface of noble metal (Au, Ag, Cu, etc.) structure resonated with specific incident light can generate the surface plasmon polaritons (SPP). The SPPs bound at the interface of metal strikingly enhance the surface electric field, and hence increase the nonlinearities like Raman scatting enhancement significantly.A symmetric SPP hybrid waveguide structure is reported, the effect of geometric structure of the waveguide on the propagation length, effective mode area, energy confinement factor, coupling length, field enhancement factor and other characters of the waveguide is studied. The simulated results demonstrate that this structure can not only realize sub-wavelength field confinement, but also propagate a relative far distance (hundreds of microns), leading to more practical SPP waveguide. Thanks to the micron-scale coupling length between parallel waveguides, the signal crosstalk between waveguides is weaker and the integration intensity of devices could be enhanced significantly.Silver torus dimer structure presented in this paper is a novel SPP nanostructure. The extinction spectra of single silver sphere(S-sphere), single silver torus(S-torus), horizontally placed silver torus dimer (H-dimer) and vertically placed silver torus dimer (V-dimer), and field enhancement factor of the dimer gap under changes of dimer structural dimension is studied. It is revealed that H-dimer has a very narrow bandwidth (10"2eV) and very small effective mode area (10-7μm2) with Purcell factor up to105magnitude, and it is one order of magnitude narrower than S-sphere of the same size. Comparing to S-torus, H-dimer increases the field enhancement by one order of magnitude to104magnitude, and increases the Raman scatting enhancement to1016magnitude (|E|4). Purcell factor and field enhancement factor of V-dimer are not good as ones of S-torus, so it has not been discussed in depth.In conclusion, noble metal hybrid waveguide and Silver torus dimer structure presented is presented, and has been simulated and analyzed using Finite Element Method (FEM), aiming to explore novel sub-wavelength hybrid waveguides with low loss and SPP nanostructures with high Purcell factor and field enhancement factor.