紫外激光诱导熔石英元件损伤增长的动态行为研究

Fused silica optical components has been widely applied in high-power solid-state laser systems at present. However, system performance has been seriously affected by the initiation and growth of damage. It belongs to a bottleneck problem and has been became one of the key factors limiting the output of system fluence. Because of this, the study on damage process and mechanism of fused silica optics is still a widely concerned focus. However, understanding of the characteristic and mechanisms of damage growth is still unclear because of the complex of this topic and the current study is still a “Static” process. In this work, It plans to base on the finite element theory, utilize finite software from theoretically. In experimental, a novel modified diagnostic method by combining ultra-fast temporal and spatial resolved diagnostic method based on the pump-probe technique with photoelasticity technique is put forward. The instantaneous dynamic process and discrepancy of damage growth during the laser energy deposition are investigated and contrasted from the formation of stress, evolution of stress wave and development of crack of the single and adjacent initiation damage site. Meanwhile, the influence of stress on crack development will be investigated. The results can futher provide an important date support on more precisely clarifying the characteristic and mechanisms, explore the mitigation method of laser-induced damage growth of fussed silica.

熔石英光学元件是高功率固体激光系统中应用最广泛的光学材料，然而元件的激光诱导损伤初始和增长已成为限制系统能量进一步提升的关键因素之一，已属“瓶颈”问题。因此对元件的激光诱导损伤过程及机理等问题的研究一直是一个广泛关注的焦点。尽管如此，由于损伤增长问题的复杂性及目前对其的研究大多属于“静态”研究，以致对损伤增长的特征及机理等方面的认识仍尚未明确。基于此，本项目拟从“动态”研究的角度出发，理论上基于有限元原理，采用有限元软件；实验上采用基于泵浦-探针原理的时空分辨超快诊断方法与光弹法相结合的新型诊断方法，重点研究和对比激光能量沉积过程对熔石英元件表面单个和相邻两种类型初始损伤点损伤增长过程中应力形成、应力波演化以及裂纹发展等问题的动态行为特征及差异，并研究应力对裂纹发展的影响。研究结果对进一步探明和阐述激光诱导熔石英元件表面损伤增长的特征和机理，以及对探讨抑制损伤增长的方法提供重要的数据支撑。

熔石英光学元件是高功率固体激光系统中应用最广泛的光学材料，然而元件的激光诱导损伤初始和增长已成为限制系统能量进一步提升的关键因素之一，已属“瓶颈”问题。因此对元件的激光诱导损伤过程及机理等问题的研究一直是一个广泛关注的焦点。尽管如此，由于损伤增长问题的复杂性及目前对其的研究大多属于“静态”研究，以致对损伤增长的特征及机理等方面的认识仍尚未明确。基于此，本项目从“动态”研究的角度出发，首先设计和搭建了一套基于泵浦-探针原理的时空分辨超快诊断方法与光弹法相结合的超快诊断系统，重点研究损伤点在损伤增长过程中，激光能量沉积过程对等离子的形成与分布，应力和应力波的产生、传播及演化过程，并研究和分析了应力对裂纹发展的影响。研究结果对进一步探明和阐述激光诱导熔石英元件表面损伤增长的特征和机理，以及对探讨抑制损伤增长的方法提供重要的数据支撑。. 项目执行过程中共发表学术论文16篇，其中SCI检索论文13篇（JCR 1区4篇，3区4篇，4区5篇，影响因子大于3的论文4篇。均按出版当年分区），EI检索论文2篇，核心期刊1篇；申请发明专利2项，截止目前为止授权1项。