AVS 63rd International Symposium & Exhibition
    Nanometer-scale Science and Technology Monday Sessions
       Session NS-MoA

Paper NS-MoA11
Strong Near-Field Coupling of Plasmonic Resonators Embedded in Si Nanowires

Monday, November 7, 2016, 5:00 pm, Room 101D

Session: Nanophotonics, Plasmonics, and Energy
Presenter: Dmitriy Boyuk, Georgia Institute of Technology
Authors: D.S. Boyuk, Georgia Institute of Technology
L.-W. Chou, Georgia Institute of Technology
M.A. Filler, Georgia Institute of Technology
Correspondent: Click to Email
We show that the near-field coupling strength between neighboring infrared localized surface plasmon resonances (LSPRs) supported in Si nanowires is ~5 times stronger than reported for conventional noble metals. We specifically measure the spectral response of selectively doped Si nanowire arrays with in situ infrared spectroscopy to demonstrate this effect. Discrete dipole approximation calculations are consistent with our experimental data, revealing that this behavior arises from a synergistic combination of the nanowire’s anisotropic dielectric structure and the large permittivity of intrinsic Si in the infrared. Our experiments reveal that the "universal" scaling of near-field coupling interactions (i.e., independent of material, shape, dielectric environment, etc.), which underlies the so-called "plasmon ruler" widely used to measure nanoscale distances in the chemical and biological sciences, is largely a misnomer. Rather, the plasmon ruler only yields accurate measurements in isotropic dielectric environments. Complex structures, including Si nanowires, require a more thorough exploration of their near-field coupling behavior. Our findings also demonstrate that equivalent near-field interactions are achievable with a smaller total volume and/or at increased resonator spacing, offering new opportunities to engineer plasmon-based chemical sensors, catalysts, and waveguides.