Surface enhanced raman spectroscopy using a single mode nanophotonic plasmonic platform
We demonstrate the generation of Surface Enhanced Raman Spectroscopy (SERS) signals from integrated bowtie antennas, excited and collected by the fundamental TE mode of a single mode silicon nitride waveguide. Due to the integrated nature of this particular single mode SERS probe one can rigorously quantify the complete enhancement process. The Stokes power, generated by a 4 nitrothiophenol coated antenna and collected into the fundamental TE mode, exhibits an 8 x 106 enhancement compared to the free space Raman scattering of a 4 nitrothiophenol molecule. Furthermore, we present an analytical model which identifies the relevant design parameters and figure of merit for this new SERS platform. An excellent correspondence is obtained between the theoretically predicted and experimentally observed absolute Raman power. This work paves the way toward a new class of fully integrated lab on a chip systems where the single mode SERS probe can be combined with other photonic, fluidic, or biological functionalities.