Differentiating the contributions between localized surface plasmon and surface plasmon polariton on a one-dimensional metal grating in coupling with a light emitter

The authors demonstrate the differentiation between the contributions of localized surface plasmon (LSP) and surface plasmon polariton (SPP) couplings with an emitting dipole to emission enhancement in a metallic grating structure. Because of the relatively higher loss and in-plane radiation of the SPP modes, the LSP modes dominate the enhancement effect. However, because the LSP resonance energy is sensitive to the metal/dielectric interface geometry, it may be difficult to precisely implement a particular geometry and achieve the emission enhancement of a desired emission wavelength based on the LSP coupling. On the other hand, because the SPP feature can be controlled by the period of a grating structure, the implementation of the SPP coupling for emission enhancement in a practical device can be more feasible. © 2008 American Institute of Physics.