Strong resonant coupling of surface plasmon polaritons to radiation modes through a thin metal slab with dielectric gratings.

Strong resonant coupling of surface plasmon polaritons to radiation modes by means of a dielectric grating deposited on top of a metal slab is numerically analyzed, and some novel properties of this configuration are discussed. The dielectric grating is not only responsible for coupling of incident light to surface plasmon polaritons but also for outcoupling of the surface plasmon polaritons to radiation modes. A key advantage of the configuration presented is that it is not based on conventional attenuated total reflection using a prism with high refractive index.