Research On The Physical Properties Of Surface Plasmon Polaritons On A Mobius Strip

Surface plasmon polaritons (SPPs) are surface electromagnetic waves on the metal surface formed by the coupling with collective oscillation by electrons and electromagnetic waves. SPPs propagating along the metal surface can produce the effect of local field enhancement and break the traditional diffraction limit. Therefore, SPPs have exhibited a wide range of attractive applications, such as nano optoelectronic devices, biological sensors, new light source, data storage and some other frontier technology. Optical microcavities confine light to small volumes by resonant recirculation and have ultra-high Q factors and ultra-small mode volumes, which can effectively enhance the interaction between light and matter. Plasmonic microcavities are based on the effect of SPPs, which provide the possibility to break the diffraction limit and can continue to reduce the mode volumes. This thesis is based on the plasmonic microcavities and studies the different mode fields of the annular and Mobius-strip type cavities via the simulation, mainly concerned on the parameter performance. The main researches of this thesis are summarized as follows:1) Researches on the different positions of Ag layer demonstrate different parameter performance of some particular modes. Mainly two distinct mode fields exist in the cavities, that is pure SPPs mode and hybrid whispering-gallery-mode. The result shows that the cavity coated with Ag layer on the external diameter has better property for practical application.2) The variation of inner diameter, external diameter and permittivity changes the performance of cavities to different extent. The size of external diameter changes the parameters linearly such that it assists to adjust the parameter performance accurately.The decrease of the permittivity can improve the Q factors without any influence on the mode volumes.3) This thesis proposes a Mobius-strip type plasmonic cavity with a silver Mobius strip sandwiched between dielectric layers. The theoretical analysis on this cavity comes first. Then the simulation reveals the field distribution in the cavity and verifies the theoretical analysis before. The comparison between M(?)bius-strip and annulus cavity with the same size indicates that the mode volumes of the former cavity are more compact. Nevertheless, the M(?)bius-strip type cavity possesses more novel properties,such as double space volume and the spatial separation, which have more potential applications.