Light-matter interactions are typically weak due to the mismatch between light waves and electronic confinement in matter. Well-designed nanostructures can function as optical "nanoantennas" to mediate and enhance the interaction between light and nanoscale objects. Such "nanoantennas" also offer the possibility to manipulate optical near fields at sub-wavelength regime and thereby to control nanoscale photochemical and photophysical interaction. Our research focuses on the understanding and engineering of nanoscale light-matter interaction by applying well-designed nanostructures. In particular, we are interested in the UV to near IR spectral window because the energy of photons in this regime is sufficiently large to promote electronic transition in matter.
Our research approach is as follows: we first perform theoretical analysis and numerical simulations to obtain optimal design of functional nanostructures for specific applications. The designed nanostructures are then realized by state-of-the-art modern nanotechnologies, such as electron-beam lithography and focused-ion beam milling. The optical responses of the fabricated nanostructures are characterized using linear and nonlinear microscopic and spectroscopic methods. The experimental results are compared with theoretical models in order to optimize the design. With this approach, we aim at a full control over the properties of light at the nanoscale.