Joël Bellessa (Institut Lumière Matière, CNRS-Université Lyon 1)

The proximity of nanostructures or metallic films to semiconductors significantly affects their properties, particularly optical ones. First, we will describe the strong light–matter coupling between organic semiconductors (J-aggregate molecules) and a surface plasmon mode. We will specifically discuss the collective effects between different molecules induced by light–matter hybridization. By structuring the material on the scale of the coherent mode extension, we will show that it is possible to create an original type of active polaritonic metasurface, as well as to achieve efficient energy transfer. In a second part, we will address structures composed of metals and inorganic semiconductors (gallium arsenide). The potential applications of these structures for the realization of surface lasers will be described.