Research On Optical Properities Of Three-dimensional Subwavelength Metal-composite Nanostructures Based On Surface Plasmons

Surface plasmon (Surface Plasmons, SPs) are evanescent wave which arepropagated along the metal surface by the interaction of photons and free-electrons.Now, the electronic information processing system and optical informationtechnology are combined by the surface plasmon effect of periodic metalnanostructures. It can be used to design many new type of nano-photonic devices.These devices can not only improve the performance of traditional electronic devices,but also can generate a lot of novel physical phenomena. It is widely used inbiophotonics, subwavelength optics, bio-molecule detection and other fields.In this work, we mainly study the enhanced transmission of subwavelength metalnano-composite structure by using the Finite-Difference Time Domainmethod(FDTD). We explore the physical mechanism of the phenomenon by changingthe parameters of the structure. At last, we also verify the existence of enhancedtransmission through experiments. The main research works are as follows:(1) Two transparent metal structure consists of flat gold film with gold ellipsoidalnanoparticle array are studied. It is discovered that both structures show an enhancedoptical transmission behavior, and the optical response can be efficiently modified byvarying the aspect ratio of ellipsoidal nanoparticles, the thickness of gold film, the gapdistance of the adjacent nanoparticles, and the environment refractive index.(2) Design a transparent metal structure consists of cylindrical metalnanoparticles and metal film. Analysis the relationship between the parameters(suchas cylinder height, location,etc) and the transmission of the structure. The innovationof the structure is using cooper as the base material of the structure. The cooper iseconomical and practical than gold and silver. And the transmission of the structure isalso very high.(3) Experimental design a sandwich structure composed of an gold film, alight-emitting layer and photonic crystal array. Measure the attenuated reflectance andfluorescence properties of the structure, and deeply analysis the physical mechanismof the optical response.