不同材料的受激布里渊散射特性

 采用波长为1.064, 0.532 μm的聚焦高斯光束作为泵浦光，数值求解受激布里渊散射（Stimulated Brillouin Scattering, SBS）放大器型耦合波方程组，比较K9玻璃、熔石英、BK7玻璃、CaF₂的SBS特征参数。研究发现：对于相同的激光参数，不同的介质具有不同的SBS特征，声子寿命长则破坏阈值低，破坏效果明显。SBS过程对CaF₂的破坏效果较明显，导致了介质前表面的破坏，在一定的激光参数和聚焦参数下，焦点附近优先于前表面破坏。SBS过程可以得到脉宽压缩比大于10、强度比泵浦光峰值高5倍以上的Stokes散射光脉冲。相同激光参数下，不同材料压缩效果及散射光相位共轭保真度不同，CaF₂在低泵浦能量时脉宽压缩特性较好；高泵浦能量时，相位共轭保真度较好。固体透明光学材料中可获得大于95%的能量提取效率。

SBS characteristics of different media

In the SBS(stimulated Brillouin scattering) amplifier the focused Gaussian beams of 1.064 μm and 0.532 μm were used as pump lasers and SBS characteristics in different medium were simulated. Through study of SBS amplifier of self-Stokes-seeding,it is found that CaF2 can be damaged more easily than fused silica or BK7 glass in SBS process.For focused pump laser,SBS may damage material from front surface.For engineering purpose,effect of energy reflectivity,pulse compression and fidelity in different SBS materials were compared.For lower energy,CaF1 has better pulse compression but worse energy reflectivity and fidelity than fused silica or BK7,while when pumping energy is high enough,the characteristics are reverse.