ABSTRACT
The considerable local field enhancement that arises from the strong light confinement result in significantly improved optical responses such as surface-enhanced Raman scattering (SERS) and metal-enhanced fluorescence. This chapter begins by revisiting Maxwell’s equation and discusses how Maxwell’s equation reflects the characteristics of surface plasmons in metal nanostructures. It highlights investigations and advances in plasmonically enhanced Raman and photoluminescence (PL) with metal nanostructures in terms of design principles and structural features. The chapter attempts to introduce and discuss metal nanostructures that have shown enhanced Raman scattering and single-photon PL with plasmonic effects in a comprehensive manner. It briefly introduces the concept of single-photon PL of metal nanostructures. In SERS, two different mechanisms contribute simultaneously to the amplification of Raman scattering signals: electromagnetic enhancement and chemical enhancement. The metal surface-based enhancement of Raman scattering signal is very important for Raman spectroscopy, because the magnitude of Raman scattering signal is very weak due to its small cross sections compared with fluorescence.
