实验研究了纳秒激光脉冲聚焦到K9玻璃内部时产生损伤的特点,并基于激光等离子体冲击波的作用原理进行了理论分析。表面损伤的特点:当激光能量较小时,在入射激光的玻璃前表面不会产生损伤。随着激光能量的增加,会逐渐出现点坑状破坏,坑的中心是一个连接体损伤的核心,围绕该点的是完全融蚀区和最外部的环状破坏区。体损伤的形貌特点是沿激光入射方向呈纺锤状,破坏区中心有一条等离子通道,四周是断裂区和折射率区。在玻璃前表面上高斯激光脉冲产生激光支持爆轰波的特点是中间部分温度最高、运动速度最快、作用压强最大,从内到外逐渐减小,所以破坏程度也逐渐减小,呈辐射状分布。而玻璃内部的体损伤特点是由激光等离子体膨胀产生的冲击波作用由里到外逐渐减小的规律所决定的。
The characteristics of nanosecond pulsed laser induced damage(LID) in K9 glass were experimentally studied,and the corresponding damage characteristics based on the principle of the interaction between the plasma shock wave and the glass were analyzed as well.The characteristics of the surface damage were that the LID on the surface didn′t occur at low incident energy.With the laser pulse energy increasing,the pit shape of LID would occur.In the center of the pit,there was a core,which corresponded to the bulk damage.Around the core was the melting region,and the outermost zone was the annular fault region.The characteristics of the bulk damage were that the damage shape was like a spindle along the laser propagation direction,and there was filamentary of plasma channel in the central area,whereas the surrounding areas were melting region,region of varying refractive index and the fracture distribution area.In the central areas of the laser-supported detonation wave induced by the Gaussian laser pulse,the motion velocity was the fastest and the pressure was the strongest since the temperature was the highest.So on the inner surface of the glass action effect of the shock wave became weaker from inside to outside,exhibiting radial distribution.However,as for the characteristics of the bulk damage,it was decided by the law of expansive action of shock wave,which became lower from inside to outside.