Ultrafast measurement of the optical properties of aluminum during shock-wave breakout - art. no. 115114

We have used high-resolution frequency domain interferometry to make ultraf ast measurements of shock-induced changes in the optical properties of thin aluminum targets. Measurements with an 800 nm probe wavelength found an un expected phase shift during a 4.65 GPa shock breakout. Further measurements at 400 nm associate this phase shift with the pressure dependence of the 1 .5 eV interband transition in aluminum. Data taken at several angles of inc idence allowed the separation of optical from material motion effects, yiel ding an effective complex index for the shocked material.