Tunable Optical Enhancement from a Mems-Integrated TiO2 Nanosword Plasmonic Antenna

In this work, we present the fabrication and testing of a MEMS-integrated, variable-gap titanium dioxide nanosword plasmonic antenna. Two-photon photoluminescence (TPPL) testing was performed, and enhancements as large as 251-fold were observed at the sharp, tapered nanosword tip. The tunable nanosword antenna successfully and repeatedly demonstrated increases in the TPPL intensity as the gap was reduced below 50 nm. Dark-field scattering experiments were performed at the tip to quantify the shape-dependent plasmonic resonance of the gold-coated nanosword tip. It is believed that this device, with further improvements to the enhancement, may enable previously unattainable functionality for surface-enhance Raman scattering (SERS) analysis.