K9玻璃与熔石英玻璃中纵向受激布里渊散射的脉宽压缩和能量提取效率

Experiments of Stimulated Brillouin Scattering for Pulse Compression and Energy Reflectivity in K9 Glass and Fused Silica

以K9玻璃与熔石英玻璃代替传统的液体或气体作为纵向受激布里渊散射(LSBS)样品,波长1.064μm,脉宽12 ns的单纵模电光调QNd∶YAG激光器作抽运光,实验上以脉宽压缩和后向斯托克斯(Stokes)散射光频移为标志,测到后向斯托克斯散射光线宽和散射光脉宽压缩比。研究了纵向受激布里渊散射样品的长度、抽运光能量大小、材料种类对纵向受激布里渊散射脉宽压缩效应和散射光能量提取效率的影响。实验结果表明,熔石英与K9玻璃的受激布里渊散射发生阈值、饱和阈值、散射光能量提取效率、散射光脉冲波形均相近,K9玻璃可以成为一种更廉价的受激布里渊散射介质。针对170 mm的熔石英玻璃样品,找到了纵向受激布里渊散射的发生阈值、饱和阈值,并得到了较高的散射光能量提取效率,从100 mm的熔石英玻璃中获得了87%的散射光能量提取效率,而从170 mm的熔石英中获得了90%左右的散射光能量提取效率。实验数据拟合的规律曲线印证了数值模拟结果。

It is investigated in fused silica and K9 glass for longitudinal stimulated Brillouin scattering （LSBS） instead of traditional medium of liquid and gas. A single longitudinal mode electro-optical Q-switched Nd： YAG laser with wavelength of 1. 064 μm is used as pump laser. Pulse compression and frequency shift of Stokes light are used to indicate the happening of LSBS. Influences of length of LSBS media and pump energy on energy reflectivity and pulse compression of Stokes light are investigated. At the same time, the characteristics of LSBS of K9 glass and fused silica are compared, which indicates that these two kind of LSBS media have not difference for LSBS. For longer medium it has higher energy reflectivity and worse effect of pulse compression; energy reflectivity of Stokes light is higher and pulse compression is not obvious for higher pump energy, High energy reflectivity of about 90% has been got in fused silica of 170 mm long and it is excited for solid LSBS medium. Fitted curves of the experimental data verify the numerical simulation results.