脉冲Nd∶YAG激光诱导水滴等离子体的实验研究  

Experimental study on water droplet plasma induced by pulse Nd∶YAG laser

作　　者：尹培琪 王新兵 武耀星 孙秦 左都罗 YIN Peiqi;WANG Xinbing;WU Yaoxing;SUN Qin;ZUO Duluo(Wuhan National Research Center for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China)

机构地区：[1]华中科技大学武汉光电国家研究中心,武汉430074

出　　处：《激光技术》2020年第6期726-731,共6页Laser Technology

摘　　要：为了研究激光诱导液滴等离子体特性,基于脉冲激光与液滴的同步作用,采用直接成像法和阴影法研究了液滴等离子体羽辉膨胀特性及激光作用液滴的运动情况。首先采用增强型电荷耦合器件直接成像法,研究了水滴等离子体的羽辉随时间的演化;其次利用阴影法研究激光作用水滴的阴影图像的演化,观察到激光作用水滴产生的冲击波及液滴团簇的变化,分析计算了冲击波膨胀距离随时间的变化和膨胀速度。结果表明,激光诱导水滴等离子体的膨胀形状近似为椭圆,其中沿激光入射方向的一侧辐射强度较高;100ns内等离子体的膨胀变化近似为线性膨胀,100ns后膨胀趋于稳定;冲击波膨胀半径随时间线性增长,冲击波的膨胀速率约为90m/s。此研究结果可为激光诱导液滴实验提供一定的参考依据。In order to study the characteristics of laser-induced droplet plasma,based on the synchronous system of pulsed laser and droplet,the direct imaging method and the shadow method were used to study the expansion characteristics of droplet plasma and the motion of droplets.Firstly,the evolution of the plume of water droplet plasma over time was studied by using the intensified charge-coupled device(ICCD)direct imaging method.Then,the shadow image evolution of laser water droplets was studied by shadow method.The changes of the shock wave and the droplet clusters generated by the laser droplets were observed,the expansion speed and the expansion distance of the shock wave with time were calculated and analyzed.The results show that the plasma expansion shape of droplets induced by laser is approximately elliptical,with one side along the incident direction of the laser having a higher radiation intensity.The expansion of the plasma within 100ns is approximately linear expansion,and the expansion tends to be stable after 100ns.In addition,the shock wave expansion radius increases linearly with time and the shock wave expands at a rate of approximately 90m/s.These findings can provide a reference for laser-induced droplet experiments.

关 键 词：激光技术 液滴等离子体羽辉 阴影法 液滴靶 

分 类 号：O539[理学—等离子体物理]