Laser Generation and Detection of Longitudinal and Shear Acoustic Waves in a Diamond Anvil Cell

Understanding of the elastic behavior of minerals under high pressure is a crucial factor for developing a model of the Earth's structure because most information about the Earth's interior comes mainly from seismological data. Several methods have been developed including Brillouin scattering, ultrasonic interferometry, and impulsive stimulated light scattering (ISLS). In view of the merit and the limitation involved in each technique, we will present an innovative approach, using laser ultrasonic in diamond-anvil cell (LU- DAC) for non-transparent materials. We will demonstrate that, using LU-DAC, it is possible to obtain directly both longitudinal and shear velocities of a non-transparent under high pressures. Preliminary data obtained on an iron foil to 23 GPa will be presented and compared with those reported earlier. Potential for extending such measurements to higher pressures and high temperatures for non-transparent materials such as amorphous and liquids will also be discussed.