Nanophotonics: basics and some potential applications for the control of light and waves.
(Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, 13013 Marseille, France)
Nanophotonics is a highly topical field of modern optics that has created new exciting technological opportunities in many areas, including medical imaging and sensor developments. Managing near-field light-matter interactions at a subwavelength nanoscale level provides new avenues to develop devices. At the seminar, we will review some key properties of the bestiary of nanophotonics: plasmonics, nanoantennas, metasurfaces and metamaterials, and show applications in a variety of fields, including MRI, PET and medical imaging.
Plasmonics and nanoantennas have the unique ability to concentrate light at a subwavelength scale, enhancing fluorescence spectroscopy for single molecule detection. Metamaterials have been proposed as a potential solution to control the emission or conversion of light. The Near Zero Index metamaterials have been proposed to design directive emitters. More recently, so-called hyperbolic metamaterials have been intensively studied. These structures possess effective permeability or permitivity tensor components such that one principal component is opposite to the two others.
Ultra-High field MRI is an imaging application that could benefit from the control of electromagnetic waves: the RF field distribution of a single channel antenna could be strongly modified by inserting resonators made of metallic wires with tunable length. It is indeed possible to design a single resonator made of hybridized dipoles whose dipolar electric and magnetic resonances can be controlled. Thanks to electromagnetic resonances and the Kerker effect, it is possible to redistribute and reshape the RF electromagnetic field in a birdcage antenna.
We will also show how these concepts could be used for other types of applications such as waterwave cloaking or seismic protection.