报告人：Shangjr (Felix) Gwo 教授
Vice President for Research and Development
Tsing-Hua Chair Professor
National Tsing-Hua University, Taiwan
题目：Plasmonic Nanoantennas and Nanolasers
Optical diffraction limits the spatial resolution of light focusing and guiding by conventional lenses, fibers, and waveguides to about the light wavelength. To date, this fundamental limit (Abbe diffraction limit) remains an insurmountable barrier for the modern developments of super‐resolution optical microscopy, photolithography, optical data storage, and integrated photonics.
Recently, the concepts of plasmonics have been successfully applied to imaging, lithography, data storage, photovoltaics, and biochemical sensing. In the early research stage, the surface plasmon-polaritons (SPPs) excited by the incident optical wave at the planar noble-metal/dielectric interface is the main means to create surface plasmons. Later on, gold and silver nanomaterials (e.g., nanoparticles or nanorods) have been introduced to generate local surface plasmon resonance (LSPR) by visible lights.
Very recently, we have demonstrated a new paradigm to realize 0-D (dimers), 1-D (linear nanoantenna arrays), and 2-D/3-D plasmonic metamaterials (artificially structured nanoparticle composites exhibiting unusual and tunable plasmonic properties) based on large-scale self-assembly and high-precision nanomanipulation of colloidal gold and silver nanoparticles.
Using these techniques, we can control not only the plasmonic resonance over the complete visible and near-infrared spectrum range, but also the subradiant (dark) or superradiant (bright) mode. Usually, plasmonic dark modes are difficult to be studied and they hold great promise for nanoantenna and waveguide applications, such as low-loss subwavelength detection, concentration, manipulation, and transport of light. Furthermore, we have been able to demonstrate the 3-D subwavelength green plasmonic nanolaser based on hybrid III-nitride (InGaN)/noble metal (Au or Ag) metal-oxides-semiconductor (MOS) nanostructures.
The nanolaser work represents a significant step toward active plasmonic components, which are critically needed to overcome the intrinsically lossy feature of passive plasmonic components.