Abstract
A laser-induced micro shock wave was observed with shadowgraphic technique. The shock wave generated on a metal surface due to laser irradiation. In this paper, a micro shock wave was induced within a low intensity energy region in the vicinity of the energy threshold. Shadowgraphic images were acquired within 1μs from laser irradiation. Under this experimental condition, in the case of in irradiation laser intensity of I_0=250GW/m^2 or less, the shock wave 1μs from laser irradiation was not able to be observed. Energy conversion efficiency was estimated by ratio of the shock wave energy to input laser energy. Here, the shock wave energy was estimated by self-similar analysis. The energy conversion efficiency increases in proportion to irradiation laser intensity.
