Abstract: Metasurfaces have an incredible opportunity to revolutionise optics through miniaturisation and enhanced light-matter interactions. While great advances have already been made in this field, the next steps beyond will require a smarter approach to metasurface design. Conventional guiding design principles usually involve time-consuming parameter sweeps over nanostructure dimensions. Even then, the desired performance may not be achieved when only simple geometries are considered. In this talk, I will introduce topology optimisation and its ability to create never-before-possible metasurface functionalities. One of which is the complete control over the polarisation state of light. I show metasurfaces with novel, multifunctional polarisation capabilities in both simulation and experiment. In the next part of the talk, I demonstrate how topology optimisation can be applied to designing metasurfaces for non-linear processes. I will focus my talk on sum-frequency generation and present metasurfaces with extremely high predicted conversion efficiencies. In addition, our algorithm can incorporate many tolerances when realising these metasurfaces, such as minimum nanostructure feature size, and minimum spectral linewidth.   

Zoom details: 

https://anu.zoom.us/j/87967197467?pwd=MDFGNGdJcXAvTWttNFpIMDJwWnNvdz09