Integrated Sideband-Resolved SERS with a Dimer on a Nanobeam Hybrid

Abstract: In analogy to cavity optomechanics, enhancing specific sidebands of a Raman process with narrowband optical resonators would allow for parametric amplification, entanglement of light and molecular vibrations, and reduced transduction noise. We report on the demonstration of waveguide-addressable sideband-resolved surface-enhanced Raman scattering (SERS). We realized a hybrid plasmonic-photonic resonator consisting of a 1D photonic crystal cavity decorated with a sub-20 nm gap dimer nanoantenna. Hybrid resonances in the near-IR provide designer Q-factors of 1000, and $Q/V=(\lambda^3/10^6)^{-1}$, with SERS signal strength on par with levels found in state-of-the-art purely plasmonic systems. We evidence Fano-lineshapes in the SERS enhancement of organic molecules, and quantitatively separate out the pump enhancement and optical reservoir contributions.