Excitation and detection of toroidal and anapole modes

Since the observations of the dynamic toroidal dipole and non-radiating anapole, the field of toroidal electrodynamics has grown rapidly paving the route to novel physical phenomena including new types of optical activity, Aharonov-Bohm effects, invisibility, and Lorentz reciprocity violations with potential applications in spectroscopy, sensing, telecommunications, and light emission. However, despite significant advances in our understanding of toroidal light-matter interactions, the excitation of toroidal and anapole modes in matter is based on heuristic approaches, which typically require complex patterning and/or illumination conditions resulting in narrowband operation and a strong background of unwanted multipole excitations. Detecting anapoles and toroidal dipoles poses an even greater challenge owing to their weak coupling to free-space radiation. Recently, Flying Doughnuts, single-cycle toroidal pulses, have been put forward as ideal probes for toroidal and anapole excitations in matter. In this talk, we will present our recent work on the light-matter interactions of Flying Doughnut pulses with simple dielectric and plasmonic systems, such as particles and films, demonstrating broadband toroidal excitations and discuss strategies for their unambiguous detection