Efficient suppression of radiation damping in individual plasmonic resonators: towards high‐Q nano‐volume sensing

Recent results on radiation damping suppression in individual plasmonic resonators using conformal bending of the structure, which suppresses the electric‐dipole response in favor of magnetic dipole one, are overviewed. It is demonstrated that bending of linear plasmonic nano‐antennas increases significantly their Q factors above the electrostatic limit while preserving the nature of resonance along with its exceptional features, such as linear size‐dependent tunability and robust field enhancement. The approach, which makes use of strong lateral confinement exhibited by the slow plasmonic modes (slow‐SPPs) bound to ultra‐narrow metallic structures, turned out to be quite general, and its experimental demonstration has been attained with circularly curved nano‐rod antennas. Furthermore, this approach suggested novel configurations of plasmonic single particle nanosensing with enhanced features, allowing record‐high figures of merit along with unprecedented spatial resolution in nanofiber‐based split‐cylinder structures.