【摘要】 研究了光强环形分布的纳秒脉冲激光对焦前铜靶的损伤形貌随脉冲功率密度的变化规律,发现在不同功率密度下,铜靶的环形损伤中,凹、凸纹的空间周期及凹凸对比度,随脉冲能量显著变化.使用熔融、蒸发、等离子体吸收和屏蔽及冲击硬化的观点,定性地解释了不同脉冲能量激光作用下烧蚀区不同形貌的成因.更多还原

【Abstract】 The damage patterns on the copper plate surface changing with the energy fluency of annularly-distributed laser pulse are experimentally studied.The copper plates are placed in front of the lens focus.It is found that the spatial period and contrast of the annular damage pattern change visibly with the energy fluency of the laser pulse.Experimental results are reasonably and qualitatively explained on account of the laser induced melt,evaporation,plasma absorption and shielding,and impact hardening.更多还原