Brillouin spectroscopy is a technique that allows us to measure acoustic sound velocity in small transparent samples up to very high pressures in a diamond-anvil cell. This technique exploits Brillouin scattering, inelastic scattering by collective thermal motions in condensed materials.
Our Brillouin spectroscopy system at GFZ Potsdam is designed to host large experimental setups (you can see the very large Eulerian cradle with a diamond-anvil cell).
Shear elastic anisotropy of ferropericlase (Mg0.9Fe0.1)O up to mid-lower mantle pressures (Marquardt et al., Science, 324, 224, 2009; Marquardt et al., Earth Planet. Sci. Lett., 287, 345)
Brillouin scattering laboratory in PETRA III
Left: spatial dispersion of acoustic velocity in a (110) plane of spinel (MgAl2O4) at high pressure in the diamond anvil cell (DAC). Center: a photo of the sample in the DAC. Right: X-ray diffraction photo of the sample in the DAC to determine its density at high pressure.