Uncertainty on Brillouin frequency on bulk polymethyl methacrylate for acoustic waves velocities

Abstract

Inelastic scattering of light by acoustic waves from a medium are known as Brillouin scattering. This effect was demonstrated by Léon Brillouin. Laser beam with high power enables Brillouin scattering thanks to acoustic vibrations in polymethyl methacrylate (PMMA). This phenomenon is known as stimulated Brillouin scattering. In our case we use a commercial bench based on the J. R. Sandercock multipass tandem interferometer design. Our study aims to gain confidence in knowing if the result given by the bench can lead to a more precise determination of the order of magnitude of the uncertainty associated with the result obtained in terms of deviation to the optical carrier. We determine the uncertainty to be ± 0.26% at 2 σ based on a modern approach. We intend to present it at the conference to give indications on the expected uncertainty terms of the microwave signal deviation of the carrier at 532 nm, characterising PMMA.