环境气压对激光烧蚀Cu诱导发光机理的影响

Effects of Ambient Gas Pressure on Excitation Radiation Mechanism in Pulsed Laser Ablation of Copper

利用时间分辨的光谱测量技术,测定了不同氪气压强下脉冲激光烧蚀金属Cu诱导等离子体发光羽的发射光谱及其强度随时间的分布。利用快速同步照相的方法,拍摄了不同氪气压强下的等离子体发光羽的照片。实验结果表明,等离子体发光羽的光谱主要由原子谱线构成,发光羽颜色随环境气压而变化。结合实验结果探讨了环境气压对脉冲激光烧蚀Cu诱导等离子体发光羽的发光机理的影响,认为不同环境气压下等离子体发光羽的发光机理不同,低压下以电子碰撞传能激发辐射为主,中压下以电子与原子碰撞传能激发和电子与一价离子的复合激发辐射为主,高压下以电子与一价离子的复合激发辐射为主,并用此机理定性地解释了所观察到的实验现象。

Time-resolved measurements of plasma plume emission spectra with pulsed laser ablation of metal Cu at different krypton pressure were reported. Taking pictures with speedy and synchronized photography, photos of optical plasma plume from laser ablation of metal Cu at different krypton pressure were obtained. The experimental results indicate that the plasma plume emission spectra were composed of atomic spectral lines, and the plasma plume colour changed with the ambient gas pressure. The effect of ambient gas pressure on the plasma plume excitation radiation mechanism in pulsed laser ablation of copper was discussed. The results are explained using a simple model based on the fact that the plasma plume main excitation radiationmechanism is changed with ambient gas pressure. The main excitation radiation mechanism in plume is electron collision energy transfer at low pressure, is electron collision energy transfer excitation radiation and recombination excitation radiation of electrons and ions at middle pressure, and is recombination excitation radiation of electrons and ions at high pressure. The model can be used to explain the experimental results qualitatively.