熔石英紫外激光损伤的尺寸演化机制与规律研究

UV-induced damage in fused silica is currently the bottle-neck problem that limits the load capacity of large, high-power laser facilities. In this regard, the mechanism and regularities concerning the size-evolution behavior of laser damage is an important part of predicting the lifetime of silica optics, which is thus of scientific significance to the safe operation of the facility. While previous studies have shown that the size of laser damage is influenced by laser parameters, predictive models of damage size as is based on laser parameters remain to be established. In this work, which focuses on the damage initiation and growth of fused silica irradiated with different pulse width, pulse shape and intensity, the trajectory of high-temperature absorption-front under high-fluence irradiation will be studied to investigate the intrinsic mechanism of size-expansion during damage initiation. Also, the statistical characteristics of surface damage growth of fused silica will be studied systematically to achieve the distribution of growth coefficient with laser parameters. Based on this study, the size-evolution model of laser damage which is suitable for high-power solid-state lasers will be established, with the contribution of laser parameters to damage evolution revealed. The aim of this work is to construct a mapping relationship from the laser parameters including pulse width, pulse shape, and light intensity to the damage size of the fused silica. The anticipated achievements of this project could contribute to deepening the understanding of high-power laser interaction with fused silica, which also provides theoretical and parameter basis for lifetime-prediction of large-aperture fused silica and operation-design for large, high-power laser facilities.

熔石英的紫外激光诱导损伤是制约高功率固体激光装置负载能力的瓶颈问题，研究熔石英损伤尺寸的演化机制与规律是实现元件寿命预测的关键环节，对装置的安全运行有重要科学意义。国内外研究表明熔石英的损伤受到激光参数的直接影响，但基于激光参数预测损伤尺寸的数理模型尚未被建立。本项目针对熔石英在不同脉宽、波形、光强辐照下的初始损伤和损伤增长问题，深入研究强激光辐照下高温吸收波前的运动轨迹，探索初始损伤尺寸扩展的内在物理机制；系统研究熔石英表面损伤增长的统计特征，获得增长系数随激光参数的分布规律；在此基础上建立适用于高功率固体激光装置的损伤尺寸演化模型，并揭示各激光参数对熔石英损伤演化的贡献差异。本项目旨在构建从包含脉宽、波形、光强在内的激光参数到熔石英损伤尺寸的映射关系，课题的研究有助于加深强激光与熔石英相互作用的认识，可为大口径熔石英元件寿命预测和装置运行策略设计提供理论基础和参数依据。

熔石英的紫外激光诱导损伤是制约高功率固体激光装置负载能力的瓶颈问题，研究熔石英损伤尺寸的演化机制与规律是实现元件寿命预测的关键环节，对装置的安全运行有重要科学意义。本项目针对熔石英在不同脉宽、波形、光强辐照下的初始损伤和损伤增长问题，深入研究强激光辐照下高温吸收波前的运动轨迹，探索初始损伤尺寸扩展的内在物理机制；系统研究熔石英表面损伤增长的统计特征，获得增长系数随激光参数的分布规律；在此基础上建立适用于高功率固体激光装置的损伤尺寸演化模型，并揭示各激光参数对熔石英损伤演化的贡献差异。本项目通过研究熔石英在激光辐照下的初始损伤和损伤增长问题，构建了从包含脉宽、波形、光强在内的激光参数到熔石英损伤尺寸的映射关系，获得适用于高功率固体激光装置的从激光参数到损伤尺寸的映射模型，课题的研究有助于加深强激光与熔石英相互作用的认识，为大口径熔石英元件寿命预测和装置运行策略设计提供理论基础和参数依据。