Coupling surface plasmon polaritons to radiation

Summary form only given. There is a continuing interest in efficiently collecting spontaneous emission, for example in light-emitting diodes and optical sources for quantum communication. Many schemes for improving the efficiency with which spontaneous emission is collected involve the use of a microcavity. Spontaneous emission is typically coupled to the lowest order mode of a microcavity, the microcavity mode in turn being coupled to radiation. We investigate an alternative approach, that of using a surface plasmon polariton (SPP) mode as the intermediate step in generating radiation. In our system the thin emissive layer is placed adjacent to a metal film rather than inside a microcavity. We report results of an investigation into the coupling efficiency as a function of the azimuthal angle between the SPP propagation directions and the Bragg vector of the corrugated metallic surface.