Momentum-resolved surface enhanced Raman scattering from a nanowire-nanoparticle junction cavity

Abstract

Herein we report experimental evidence of directional SERS from molecules situated inside a single nanowire-nanoparticle junction cavity. The emission was confined to a narrow range of wavevectors perpendicular to the axis of the cavity. In addition to this, the molecules excite multiple guided modes of the nanowire which were imaged using leakage radiation Fourier microscopy. We further characterize the emission wavevectors as a function of output polarization. The excited guided modes of the wire show interesting polarization signatures. All the results were corroborated using finite element method based numerical simulations. Essentially, we provide an important connection between gap-cavity enhanced Raman scattering and its directionality of emission. The results may be of relevance in understanding the cavity electrodynamics at the nanoscale and molecular coupling to extremely small gaps between a one dimensional and a zero-dimensional plasmonic nanostructure.

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Cited by in corpus (4)

• Directional emission from WS2 monolayer coupled to plasmonic Nanowire-on-Mirror Cavity
• Ultrabroad resonance of localized plasmon on a nanoparticle coupled with surface plasmon on a nanowire enabling two-photon excited emission via continuous-wave laser
• Mirror enhanced directional out-coupling of SERS by remote excitation of a nanowire-nanoparticle cavity
• Experimental observation of transverse spin of plasmon polaritons in a single-crystalline silver nanowire