Influence of surface roughness on nanosecond laser-induced shock wave enhancement effects

In this paper, an effective method is proposed for improving the energy of the shock waves that are generated by plasma expanding outward and colliding with another gas. Silicon targets are used as the response medium with roughness of 2.3 nm, 457.8 nm, 1.1 µm, and 37.1 µm, respectively. A 532-nm-laser with a pulse duration of 8 ns and a repetition rate of 10 Hz is used as the irradiation source. An intensified charge-coupled device (ICCD) is used to photograph the morphology of the shock waves. The time-resolved emission images of silicon plasma plumes are observed between 20-200 ns. As the surface roughness of the target increases, the intensity of the shock wave gradually increases, and the energy of the shock wave reaches up to 39.45 mJ at a roughness of 37.1 µm.