New progress of plasmonics in complex metal nanostructures

Abstract

Noble metal nanostructures possess novel optical properties because of their collective electronic oscillations, known as surface plasmons (SPs). The resonance of SPs strongly depends on the material, surrounding environment, as well as the geometry of the nanostructures. Complex metal nanostructures have attracted research interest because of the degree of freedom in tailoring the plasmonic properties for more advanced applications that are unattainable by simple ones. In this review, we discuss the plasmonic properties of several typical types of complex metal nanostructures, that is, electromagnetically coupled nanoparticles (NPs), NPs/metal films, NPs/nanowires (NWs), NWs/NWs, and metal nanostructures supported or coated by dielectrics. The electromagnetic field enhancement and surface-enhanced Raman scattering applications are mainly discussed in the NPs systems where localized SPs have a key role. Propagating surface plasmon polaritons and relevant applications in plasmonic routers and logic gates using NWs network are also reviewed. The effect of dielectric substrates and surroundings of metal nanostructures to the plasmonic properties is also discussed.