Wednesday 12 June 2019 - 14:00

Department of Physics Nova School of Science and Technology

Room 213

Boosting the performance of nanoantennas in sensing, spectroscopy and non-linear optical applications

Metallic nanostructures showing plasmon resonances can act as optical nanoantennas, providing a versatile tool to control light beyond the conventional diffraction limit and enabling many applications such as ultrasensitive (bio-) sensing or surface enhanced spectroscopies. However, plasmonic excitations are known to be affected by relatively large losses and the absence of magnetic response at optical frequencies. This unavoidable problem together with the ambition to have more control over light-matter interaction, made researchers to go beyond plasmonics. Recently, nanoparticles made of High Refractive Index dielectric materials have been proposed as an alternative to metals driven by their low-losses and magnetic response. The coherent effects between the electric and magnetic resonances are responsible for their exceptional directionality properties that make them attractive to boost applications where enhancing light-matter interaction and controlling the radiation direction is extremely relevant. These nanoparticles, when used as unit-cells of more complex systems, such as metasurfaces, result to be essential in the design of novel optical devices. Their low-losses, strong confinement of electromagnetic energy and the outstanding scattering efficiencies show these nanostructures as promising candidates for the next generation of nanoantennas that may be able to boost the Surface Enhanced Spectroscopies, non-linear phenomena or sensing applications. In this talk, I will describe and discuss the origins and recent advances in this rapidly developing field of dielectric nanophotonics, paying special attention to the main significant contributions we have done since its startup to boost its progress.