超快脉冲激光烧蚀动力学研究

Extensive studies have so far been done for pulsed laser ablation and the related laser radiation-condensed matter interactions. Pulsed laser ablation has been successfully used for film depostion, material etching, composition analysis etc. Because of the strong non-equilibrium processes involved，especially because of the difference in the mechanisms of interactions between laser pulse and material when using different pulse duration, the details of pulsed laser ablation are not clear yet. In this project, by examing the time and space evolution of the ablation plasma and the time and space behavior of the ablation products, the dynamics of ns-fs pulsed laser ablation was studied. We nvestigated the occurrence of material ablation, the formation and expansion of the plasma, the excitation and relaxation of ablation products and the influence of gaseous background etc. We found that ablation products in different energy states behave very differently in time and space, and that their time and space baehaviors depend strongly on the gasious background, especially on the width of the used laser pulses. On the basis of the investigation of the ablation dynamics, we made attempts to explore the applications of pulsed laser abltion in given background for the synthesis and preparation of compound films and the detection of trace elements in materials. For the latter, we got a detection sensitivity of sub-ppm by analysing the optical emission from the cooled plasma with proper means in order to reduce the interference of plasma contiuum.

以批秒和非秒脉冲激光烧蚀为对象,通过对烧蚀产物的时间,空间分辨的质谱和光谱分析,考旄吖β拭芏瘸碳す饴龀宥怨烫宓淖饔?固体表层的烧蚀,烧蚀产物的运动,激光烧蚀等离子体的产生和膨胀等,着重研究纳秒和批秒时间域动力学过程和无能量注入的烧蚀等离子体的莼?并在此基础上探索超短脉冲激光烧蚀在薄膜沉积和成分分析上的应用.