Optomecanics and nanostructures

Head : Dr. B.Besga and Dr. J.Margueritat

Members: B.Mahler, J.Houel 

Matter vibrates at all scales! We are interested in the interaction of these vibrations (from 100 MHz to 10 THz) with photons. 
On the one hand, we characterize the spontaneous vibrations of matter using inelastic light spectroscopy (Raman, low frequency Raman and Brillouin). We can thus characterize mechanical properties of a bulk material by studying the propagation of acoustic waves in or on the surface of a material. When the scale is reduced to dimensions smaller than the acoustic wavelength, typically for a 100 nanometer nanoparticle, the acoustic waves are confined and the vibrations modes of a nanoparticle as a whole can be observed, allowing deductions to be made about its size, shape, composition, surface state or direct environment. 
On the other hand, these vibrations can be enhanced and controlled by optical stimuli, which will then allow us to detect them directly with interferometric measurements at very low frequency in order to understand and use the interaction of these vibrations with intrinsic properties of materials like exciton luminescence. 

By improving our understanding of vibrations in matter (from biological materials to luminescent particles via silica nano-membranes or teeth), by using experimental devices at the limit of the state of the art (single particle spectroscopy, optical nano-trap, Brillouin goniometer…), we are progressively developing novel optomechanical systems made up of single nanoparticles or assemblies of nanoparticles.

Some recent publications :

Single gold NC vibration
JPCC (2022)

Study of Single Gold Nanocrystals by Inelastic Light Scattering Spectroscopy

Mariana M Timm, Lucien Saviot, Aurélien Crut, Nicholas Blanchard, Lucian Roiban, Karine Masenelli-Varlot, Lucile Joly-Pottuz, Jérémie Margueritat

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