Plasmon Enhanced Nonlinear Spectroscopy and Imaging

Surface Plasmon (Surface Plasmon) is a phenomenon in which electrons on a metal surface collectively oscillate under the action of an external electromagnetic field, see Fig. 8.1. It is divided into Local Surface Plasmon Resonance (LSPR) and Surface Plasmon (Surface Plasmon). Polariton, SPPs) two kinds. LSPR is a conductive electron resonance phenomenon generated at the interface of positive and negative dielectric constant materials under the excitation of incident light. At the resonance wavelength, the near-field field strength is enhanced. This near field is highly concentrated in the nanoparticle and decays rapidly as it moves away from the nanoparticle/dielectric interface into the dielectric substrate. The enhancement of light intensity is an important aspect of local surface plasmon resonance. Localization means that LSPR has a very high spatial frequency (sub-wavelength) and is only limited by the size of nanoparticles.