布里渊散射是指入射到介质的泵浦光束与介质内的弹性声波声子发生相互作用而产生的三阶非线性光散射现象。在受激布里渊散射（SBS）脉冲压缩过程中，时域脉宽压缩研究较为广泛，但压缩过程中频域线宽变化与介质粘度、折射率等特性密切相关，因此文中研究聚焦单池结构下SBS脉冲压缩过程中介质FC-770产生的Stokes线宽变化影响因素，发现随着泵浦能量的增加，Stokes线宽先迅速增加后逐渐压窄至400 MHz左右，而随着产生池前透镜焦距的逐渐减小，Stokes线宽迅速压窄，且随能量变化线宽变化范围减小，最后探究了入射激光线宽对Stokes线宽变化的影响因素，得出介质FC-770产生的Stokes线宽值与入射激光线宽呈正比例关系，入射激光线宽值由280 MHz变化到450 MHz左右时，输出的Stokes线宽值由500 MHz变化到680 MHz左右。

受激布里渊散射（SBS）作为三阶光学效应广泛应用于激光组束、分布式光纤传感、布里渊激光器等领域。近年来，SBS脉冲压缩亦得到特殊关注。基于布里渊放大过程中的能量转移特性，SBS脉冲压缩技术能够将ns量级脉冲压缩至亚ns量级，峰值功率可提升1～2个数量级。系统介绍了SBS脉冲压缩基本理论，综合论述了SBS压缩器结构、增益介质、泵浦脉冲等因素对脉冲压缩特性的影响，并对SBS脉冲压缩发展趋势进行了展望，为今后SBS特性的研究提供了有益参考，也为高重频、高能量激光的获取提供了可行方案。

We present a single-mode multilayer-core fiber with a large mode area (LMA) and a low bending loss in this Letter. A low equivalent core-cladding refractive index difference is achieved by exploiting the multilayer structure. The multilayer structure has a better bending performance than a traditional step-index core and this structure also contributes to realizing different curved refractive index profiles that have a better bending performance. An index trench is also introduced to dramatically reduce the bending loss. The experimental results show that, at a wavelength of 1550 nm, the mode area of the fabricated fiber is about 215.5 μm2 and the bending loss is 0.58 dB/turn at a 10 mm bending radius. The LMA and excellent bending performance can be obtained simultaneously with the proposed fiber.