The acceleration phenomenon of shock wave induced by millisecond-nanosecond combined-pulse laser on silicon

Silicon is an indispensable raw material in the manufacture of electronic devices, and it is widely used in aerospace field. We study the motion morphology and velocity of LSW induced by millisecond-nanosecond combined-pulse laser with different pulse delay and laser energy density irradiating silicon based on the method of laser shadowgraphy. Experimental results show that when the pulse delay is 2.4 ms, the millisecond(ms) and nanosecond(ns) laser energy density is 301 J cm−2 and 12 J cm−2, respectively, the velocity of shock wave is 1.1 times faster than that induced by single ns pulse laser. It is inferred that the shock wave propagates in the plasma is faster than that in air. The results of this research can provide a reference for the field of optimized laser propulsion.