The physics of interactions between light and small particles dates back to the time of Lord Rayleigh and Gustav Mie whose theories describe naturally occurring scattering phenomena such as sky hue and colour of clouds. Nanotechnology shines new light on the old theories as it allows the reverse-engineering of the light scattering processes, i.e. to design and fabricate nanoparticles with optical properties at will. This enables unusual light-matter interactions, most remarkably, strong magnetic response at optical frequencies.  Artificially engineered magnetic response gave rise to a new direction of research: meta-optics. This drives a tremendous progress in the field of metasurfaces – ultrathin flat optical components consisting of resonant nanoparticles. Today our all-dielectric metasurfaces match or outperform conventional optical elements while being hundreds of times thinner than paper. Metasurfaces are becoming an established technology and they find their applications in other areas of science and in industry. And as meta-optics continues to evolve, we look beyond classics of linear light scattering and foresee the great opportunities in nonlinear, quantum, and topological nanophotonics driven by engineered magnetic responses.

Sergey Kruk received his PhD in physics from the Australian National University in December 2015, and has been involved in theoretical developments, nanofabrication and optical experiments with antennas for light, metasurfaces and metamaterials. He currently serves as a Research Fellow at the Nonlinear Physics Centre working on functional all-dielectric nanophotonics.