Over the last century, numerous structures have been developed in electrical engineering to help the radiation of electromagnetic waves at microwave frequencies. The recent advances in nanofabrication techniques have enabled the realization of similar structures that now operate at optical frequencies. Taking advantage of plasmon resonances in metals enables the excitation of extremely strong fields within the antenna, a phenomenon that does not have a classical equivalent at microwave frequencies. In turn, these fields can be used to enhance and localize optical radiations within nanoscopic volumes, thereby making possible the control of optical processes in molecules. In this presentation, the functioning principles of plasmonic antennas and their fabrication will be described. Two experiments will be emphasized: the selective Raman enhancement for molecules deposited on antennas and the trapping of particles as small as 10nm within the gap of plasmonic antennas.
The language of the presentation is English.
Free entrance, guests are welcome