Near field optomechanics in photonic systems
P.I.: Thomas Antoni
Optomechanics designates the coupling of an electromagnetic wave with the motion or vibration of an object, enabling, for example, mechanical manipulations with light. Of course, this interaction is as strong as optical powers are important or as the objects are small. But, even more interesting, if the size of the object is on the order of, or smaller than the wavelength, the coupling occurs through evanescent waves creating huge local intensities that further enhance the effect.
Experimental tools
We developed a Michelson interferometer able to measure displacements or vibrations as small as 10-12 m of microscopic structures, at ambient or low pressures.
Modeling
The optical design of the photonic structures and computation of the optical forces is performed using Finite Difference in Time Domain open-source MEEP code, or MPB eigen solver, both developed by MIT.
Ongoing projects
Enhancement of radiation pressure with surface plasmon
Metallic nanoparticles support surface waves due to plasmon polaritons, but their resulting optical behavior (absorption or scattering), dramatically depend on their size. We numerically investigate how optomechanical coupling can be magnified depending on the size of the particle and their environment. In scope of applications to biological systems the particle is considered inside a microfluidic channel (Figure).
D polymer optomechanical resonators
Historically, most micro- or nano-optomechanical resonators are fabricated in semiconductor materials due to the high level of maturity of their processing. But, first, these techniques only allow the fabrication of 1D or 2D structures. On the other hand, 3D microfabrication has been made possible with polymer materials via Low One Photon Absorption techniques developed in the team of Diep Lai who with we are willing to use this extra-degree of freedom to explore either new optical or mechanical features and their coupling.
Optomechanics with photostrictive materials
If piezoelectric materials change their dimensions when a voltage is applied, under certain conditions a similar effect called photostriction can occur when illuminated by an intense optical beam. The experimental techniques we developed to study radiation pressure optomechanical coupling are a promising tool to investigate this novel effect. This work is a collaboration with the SPMS lab (CentraleSupélec).
Partners: Pierre Verlot (Univ. Notthingham, UK) ; N. Diep Lai (LuMIn) ; Charles Paillard, SPMS (CentraleSupélec, Univ. Paris-Saclay, France).