Brillouin light scattering for the characterization of bulk and bulk and surface elastic waves

International audienceBrillouin scattering reveals acoustic or spin-wave frequenciesin the microwave frequency domain. Brillouin light scattering (BLS) setup deals with the detection and analysis of laser light scattered by fluctuations of refracting index in a medium. It consists in analysis of the refracted light emitted by a material. Tandem Fabry–Perot interferometer produces peaks shifted from the frequency of the laser to characteristic frequencies depending on the material. As a way of calibration, we can characterized different bulk materials such as for example glass, PMMA, nylon, polypropylene, Lithium-aluminosilicate glass ceramic or thin layers. From BLS we can deduce parameters of the material like phase velocity of transverse and longitudinal waves