Surface plasmon polaritons: physics and applications

Surface plasmon polaritons (SPPs) are electromagnetic excitations existing at the interface between a metal and a dielectric material. Remarkable progress has been made in the field of SPPs in recent years. Control and manipulation of light using SPPs on the nanometre scale exhibit significant advantages in nanophotonics devices with very small elements, and SPPs open a promising way in areas involving environment, energy, biology and medicine. This paper presents an overview of current research activities on SPPs, including fundamental physics and applications. We first discuss the excitation of SPPs based on the SPP dispersion relation, coupling to SPPs by momentum matching between photons and SPPs, and propagation behaviour of SPPs. Based on the physical mechanism and the peculiar properties of SPPs, we demonstrate the major applications of SPPs, such as waveguides, sources, near-field optics, surface-enhanced Raman spectroscopy, data storage, solar cells, chemical sensors and biosensors.