脉冲激光烧蚀碲镉汞材料的等离子体发射谱

脉冲激光辐照处于不同背景气压下的Hg0.8Cd0.2Te材料表面，用时间和空间分辨诊断技术探测了激光照射后产生的等离子体发射谱，根据所获得的飞行时间谱测量了等离子体中粒子的出射速度，结果表明粒子速度随着出射距离的增加迅速减小，且背景气压对出射速度有很大的影响，而激光能量对粒子速度的影响不大。另外根据谱线的展宽计算了等离子体中的电子密度，结果表明，电子密度在激光辐照样品后的短时间内迅速减小，且电子密度最大的位置不是出现在靶的表面而是在距表面一定距离处。

The Emission Spectrum of Plasma Induced by Pulsed Laser Ablation of HgCdTe

At different pressure, a pulsed laser was used to irradiate the surface of Hg0.8Cd0.2Te. The emission spectrum from the plasma was detected by a time and space-resolved diagnostic technique. The velocity of the ejected particle was measured on the basis of obtained time of flight spectrum. The experimental results indicate that the velocity of the ejected particle decreases quickly with increasing the distance from target surface. Moreover, the velocity is influenced greatly by the ambient pressure and the laser energy has almost no impact on velocity. In addition, the electron density was estimated by using full width at half maximum and the results show that the electron density decreases quickly during a short period after the laser arrives the surface. Moreover, the maximal electron density emerges at a position which is some distance away from the target surface but not on the surface.