Improved laser-ultrasonic excitation for imaging of seismic physical modeling

In this study, a laser ultrasonic technology (LUT) was employed for seismic physical model (SPM) imaging. To promote an efficient light-to-ultrasonic-wave conversion, a functionalised Au film was used as a medium because of its stronger photoacoustic (PA) effect. Numerical analysis and experiments were performed to characterise the entire SPM imaging process, including the generation of PA signals, transmission of PA inside the SPM, and collection of echo data for the reconstruction of SPM images using the time-of-flight algorithm. The results show that the Au film coating on the SPM produces a strong PA effect, which significantly improves the imaging depth and resolution of the SPM based on the strong high-frequency ultrasonic wave excitation. The proposed method opens new avenues for SPM imaging using optical technology.