Research Area

Dielectric metasurfaces can support various Mie-type resonances that can be used for directional scattering of light, perfect absorber and enhanced light-matter interactions, etc. We use home-built, python-based FDTD simulation code to calculate optical properties of metasurfaces and analyze their multipole nature.

Figures: (left) electric near-field profile of a dielectric cube resonator exhibiting magnetic dipole mode. (right) multipole expansion analysis of a metasurface comprising an array of cube resonators.

Due to the Drude-like nature of free electrons, metals can efficiently confine and enhance long-wavelength radiations when patterned to the nanoscale. We design, fabricate, and optically measure metallic nano-gaps and find their applications in sensing and optoelectronic devices for 5/6G communications.

Figures: (left) metallic nano-gap structures fabricated on a flexible wafer. (right) high-contrast detection of ultrasmall volumes of liquids in terahertz frequencies, enabled by metallic nano-gaps.

Interaction of matter with strongly enhanced electromagnetic fields leads to many interesting phenomena including Purcell effect, high harmonic generation, and strong coupling, etc. We attempt to combine the aforementioned nanostructures with various nanomaterials such as quantum dots and 2D materials to investigate highly efficient, next-generation optical devices.

Figure: a schematic image of a 2D material integrated with dielectric metasurface for strong modification of excitonic emission via Purcell effect.