Investigation Of Hybrid Waveguide Design And Ag Nanosphere Localized Surface Plasmon Induced Dipole-Dipole Interaction

In order to obtain a more compact low-loss waveguide structure, based on the surface plasmon of the metal waveguide has been extensively studied in recent years. A novel hybrid waveguide structure of rectangular silicon insert two identical nuclei in a rectangular metal trench is presented. Based on the finite element method, variations of effective mode area and propagation distance with distance between the two nuclear medium, nuclear medium height and width, the distances between dielectric core and metal are systematic studied at a wavelength of 1550 nm.The calculated results show that the enhanced effect of field in gaps of the dielectric core(Si) or between dielectric core and metal can get a low loss hybrid mode of ultra-small modal area. When the distances between dielectric core and metal are wide, the gap in dielectric core is 5 nm, effective mode area of the structure is drastically reduced to about one-seventh respect to the nuclear medium with no gap and the propagation distance increasing a slight remains at 50 wavelengths around. And the smaller the mode area is, the longer the propagation distance is. The higher the gap dielectric core is, the smaller the propagation distance is, and the mode area is almost invariable. When the height of dielectric core is higher, the propagation distance is longer, but the effective mode area changes minor. When the distances between dielectric core and metal are narrow, the gap of nuclear medium and nuclear medium width are much narrower, the effective mode area are smaller.Metal nanosphere(MNP) is a promising platform to investigate the quantum resonant dipole-dipole interaction(RDDI). We use the photon Green-function method to study the quantum RDDI induced by an Ag nanosphere(ANP).As the distance between the two dipoles increases, the RDDI becomes weaker,accompanied by the influence of the higher-order mode of the ANP to RDDI declines more quickly than that of the dipole mode. Across a broad frequency range(above0.05eV), the transfer rate of the RDDI is nearly constant as the two dipoles fixed at the proper position, in addition, this phenomenon still exists for slightly different radius of the ANPs. We find that the frequency corresponding to the maximum transfer rate of RDDI exhibits a monotonic decrease by moving away one dipole but the other dipole and the ANP are fixed. In addition, the radius of ANP has little effect on that. As the two dipoles are far away from the ANP, the maximum transfer rate of the RDDI takes place at the frequency of the dipole mode. In contrast, when the two dipoles are close to the ANP, the higher-order modes come into effect and play a leading role in the RDDI if they match the transition frequency of the dipole.