Over the past five years, meta-optics has become an independent, rapidly developing field that has contributed to cutting-edge photonics- and optics-based technologies. Meta-optics focuses on the two-dimensional version of metamaterials, namely metasurfaces, and their constituent elements, meta-atoms. In the majority of cases, these are subwavelength resonant structures with cavity-like nature, which can enhance or reshape light-matter interactions. The material, arrangements of structural elements and excitation of optical modes play a crucial role in controlling light localisation, polarisation conversion, and nonlinear optical effects. 

In this talk, I will present experimental illustrations of metasurface-type structures possessing topological properties as well as a subwavelength nanostructure revealing nonlinear circular dichroism. Then, I will explore the use of unconventionally polarised laser beams, their topological characteristics and applications. I will also introduce the approaches to creating vector beams by metasurfaces. Next, I will show how to utilise such vector beams of azimuthal and radial polarisations for observing the Fano-profile spectral features and those associated with bound states in the continuum in the optical response of a single nanoresonator. I will conclude by discussing the role of laser pulse duration in measuring the quality factors of the corresponding resonances, together with the experimental demonstration of record-high up-conversion efficiency at the nanoscale enabled by a single resonator.