Plasmon induced transparency in metamaterials controlled by light

Over the last two decades, metamaterials have experienced a strong development due to unusual electromagnetic properties such as optical magnetism, negative refraction or bianisotropy. Among these properties, the observation of Fano resonances has focalized great interest. Fano resonance results from the interference between two resonators, one with a large spectral width, the other with a narrow resonance. These conditions can be satisfied using tunable coupled plasmonic structures. The Fano resonance phenomenon is accompanied by original optical properties such as plasmon induced transparency (PIT), which has led to innovative applications (single molecule detection, optical switches, interferometers, nanoantennas). In materials showing PIT, nearly full transparency can be achieved through coherent coupling between two resonators generating destructive interference within the absorption spectrum of the broadband resonator. Although observed in isolated plasmonic structures, the transposition of these properties to large scales is a great challenge due to nanofrabrication process limitation. The project aims to address these fundamental aspects by using innovative fabrication process that allows precise control of the plasmonic nanoparticle assembly over wide areas. One of the objectives is to transpose PIT properties to metamaterials. The project relies on the use of SAMs coupled to deep-UV interferometric lithography to generate either chemical or topographical contrast over wide area in a single exposure which allow to selectively organize nanoparticles on the surface. Beyond manufacturing steps, our approach includes a post-functionalization of the metamaterials by photochromic molecules to achieve photomodulation of the assembly optical properties. As surface plasmon resonances are sensitive to refractive index, its control through the photochromic isomer state will ensure reversible modulation of the Fano / PIT properties.

For more information, contact Dr G. Laurent

You can apply on the dedicated website of the Université Paris-Saclay