大型光学元件中的横向受激布里渊散射

研究大型光学元件中横向受激布里渊散射的特点和破坏机制,以及横向受激布里渊散射的抑制方案。在理论分析的基础上,进行数值模拟。当入射光强足够高,材料的横向尺寸足够大时,在受激散射过程中产生的弹性声波场有可能超出材料的抗拉强度,从而引起力学破坏;增加泵浦光带宽可以显著降低散射光的增益。强激光辐照下的大尺寸光学元件中很容易激发横向受激布里渊散射;对于大多数强激光系统,20GHz的带宽已经足以抑制TSBS带来的影响。

Transverse stimulated brillouin scattering in large optics

The objection of this paper is to discuss the main characteristics and induced damage mechanisms of TSBS in large optics,and the suppression of TSBS due to finite laser bandwidth.It is realized by way of numerical simulations on the ground of theoretical analysis.The investigation shows that the strength of the elastic acoustic waves may surpass materials' yielding ability and induce mechanical damage when the pump laser intensity is sufficiently high and the transverse scale of optics is sufficiently long,and even small amounts of laser bandwidth can reduce gain obviously.Finally,we obtain the results that TSBS can be induced easily in large optics exposed to high intensity laser,and 20GHz will lead to enough reduction in the SBS gain.