Shock Parameter Measurement of Sub-Micrometer Aluminum Driven by Laser Using Frequency Domain Interferometer

For aluminum films with submicron thickness deposited on quartz substrates, femtosecond laser pulses (35 fs pulse width, 0.5 mJ energy, and a central wavelength of 800 nm) were focused on the surface to induce rapid thermal expansion through laser ablation. This process generated shock wave propagation and achieved high-pressure loading on the aluminum samples. Through the quartz window on the backside of the aluminum sample, frequency-domain interferometry was employed to simultaneously measure shock-induced radial displacement profiles, particle velocities, and shock wave propagation velocities. Experimental repeatability for multiple shots was enhanced through pulse energy and shock position monitoring. A phase comparison algorithm was applied for data analysis, achieving sub-nanometer displacement resolution and sub-picosecond temporal resolution. This methodology successfully captured the interfacial shock profile evolution history in the aluminum film under approximately 130 GPa of pressure.