Enhancement of Light - Matter Interaction in Metal - Dielectric Nanostructures

Abstract

So-called plasmonic nanostructures comprising nanotextured metal surfaces or dispersed metal nanoparticles in a dielectric medium offer strong enhancement of light matter interaction with respect to atoms, molecules, nano- and microrystalline probes deposited thereon or embedded therein. Mechanisms and experimental performance of Raman scattering and photoluminescence enhancement are considered in the context of their application in high sensitive spectral analysis. So-called “hot spots” are treated as local areas in plasmonic nanostructures where high Q-factors develop both for incident light frequency and for emitted or scattered light frequency. Rationale is provided for 1014 enhancement factor for Raman scattering which has been claimed based on experimental observation but to date has never been reported in the theory. Recent results on efficient Raman scattering enhancement of micrometer-size crystallites by means of nanometer-size metal particles are discussed. Feasibility of 10- to 102-fold enhancement is highlighted for luminescence.