Doughnut-shaped emission from vertical organic nanowire coupled to thin plasmonic film

Abstract

Vertical nanowires facilitate an innovative mechanism to channel the optical field in the orthogonal direction and act as a nanoscale light source. Subwavelength, vertically oriented nanowire platforms, both of plasmonic and semiconducting variety, can facilitate interesting far-field emission profiles and potentially carry orbital angular momentum states. Motivated by these prospects, in this Letter, we show how a hybrid plasmonic-organic platform can be harnessed to engineer far-field radiation. The system that we have employed is an organic nanowire made of diaminoanthroquinone grown on a plasmonic gold film. We experimentally and numerically studied angular distribution of surface plasmon polariton mediated emission from a single, vertical organic nanowire by utilizing evanescent excitation and Fourier plane microscopy. Photoluminescence and elastic scattering from a single nanowire was analyzed individually in terms of inplane momentum states of the outcoupled photons. We found that the emission is doughnut-shaped in both photoluminescence and elastic scattering regimes. We anticipate that the discussed results can be relevant in designing efficient, polariton-mediated nanoscale photon sources that can carry orbital angular momentum states.

High-directivity far-field radiation of quantum dot-based single-photon emitter coupled to polymeric circular waveguide resonant grating

“…In addition, we utilized a flip mirror mechanism to activate a back-focal plane imaging system with a configuration similar to other studies [32][33][34][35]. The back-focal plane image of the objective lens was captured using a CMOS camera for a spectrally integrated analysis of the far-field radiation pattern.…”