项目名称： 高功率激光光学材料中的光-声相互作用研究

项目编号： No.U1530109

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 邱荣

作者单位： 西南科技大学

项目金额： 64万元

中文摘要： 随着光学材料生产和元件加工技术的不断改进，光学元件中的杂质和缺陷逐步得到控制，这提高了高功率激光系统的输出能力。但是，随着激光功率增加，由电致伸缩效应引起的受激布里渊散射逐渐增强，严重制约系统输出功率的进一步提升和运行安全。这种现象在ICF驱动激光装置中尤其明显，其理论模型和数值模拟方法并不完善，对其理论的实验验证和有效的抑制方案还研究甚少。本项目围绕提高大口径熔石英元件损伤阈值这一目标，拟建立三维含时横向受激布里渊散射的理论模型，及受激布里渊散射与小尺度自聚焦相互作用的理论模型，并数值模拟其物理过程；结合对该过程的光学、力（声）学和损伤特性的时空分辨实验研究，以及在神光Ⅲ原型装置上开展在线原位实验研究，分析受激布里渊散射对元件破坏的物理机制，寻找抑制受激布里渊散射的方法和措施。本项目的研究可作为新型激光材料研制、高功率激光系统设计的技术支撑，对发展超高功率激光驱动器有重要意义。

中文关键词： 高功率激光；熔石英；激光诱导损伤；受激布里渊散射；损伤机制

英文摘要： With the developments of the optical materials producing and processing technological, impurity and defects of the optical material is well controlled recently. With powerful laser beams, stimulated Brillouin scattering (SBS) will be excited by electrostriction of the bulk medium and no linear absorption occurs, which becomes more obvious in the regions of high fields. By increasing the local pressure, an excited acoustic wave on which a Stokes wave scatters in the backward direction can damages the front surface of the sample at high laser powers. This may limit the output power of the systems and affect the operation safety negatively. This kind of phenomenon is especially serious in the ICF (inertial confinement fusion) laser devices, and the current theoretical model and numerical simulation method is not accurate. Further experimental study on the relevant theory and the suppression technology are necessary. This project aims to improve the damage threshold of the large-diameter fused silica components. The theoretical models for full space-time (3D+1) transverse stimulated Brillouin scattering (TSBS), as well as the interaction between the SBS and the small-scale self-focusing, will be established. The corresponding physics processes will be simulated numerically. Based on the space-time experiment for the optics, mechanics (acoustics) and damage characteristics, and the online experiment on the SGⅢ Prototype, the mechanism of that the SBS causes damage in laser components will be analyzed, in order to develop methods and techniques to suppress SBS. This study is helpful to the development of new laser materials, and the design of the high power laser systems. Moreover, the result will be of great meaning for super-high power lasers.

英文关键词： high power laser;fused silica;laser-induced damage;stimulated Brillouin scattering;damage mechanism