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摘要 将波长 1064 nm，脉冲宽度 8 ns 的 Nd:YAG 激光脉冲聚焦到 FC-72 介质池中，利用 CCD 对后向受激布里渊 散射(SBS)光斑进行检测，并利用数字图像处理技术对图像进行分析，以获得 SBS 光斑的空间光强分布和变化规律。 利用 MATLAB 的图像处理工具箱对激光光斑的原始 CCD 图像进行去噪,并使用 Origin 软件的曲线拟合和 FFT 平 滑功能对光强分布曲线进行平滑处理。 结果表明,进行图像处理后的原图像噪声被有效地抑制和消除,光强分布曲线 较为平滑。在入射光束为基模高斯光束的条件下，随着入射光能量增大，受激布里渊散射光斑的空间光强分布由近 高斯型转变为高斯型。 关键词 检测；受激布里渊散射；光强分布；图像处理 中图分类号 aeö ç÷ ç÷ èø ，Abstract By focusing laser pulses with wavelength 1064 nm and pulse width 8 ns into FC-72 medium, the intensity distribution of backward stimulated Brillouin scattering (SBS) spot is investigated experimentally by CCD camera. The images are analyzed by digital image processing technology to obtain the spatial intensity profile and evolution of SBS spot. Using the image processing toolbox of MATLAB, the noise removing treatment on original CCD image of laser spot is performed. And the smoothing treatment on intensity distribution curve is achieved by using the curve fitting and FFT smoothing functions of Origin software. The results show that the noise of original image is effectively suppressed and ridded after the preprocessing treatment, and the intensity distribution is comparatively smooth. On the condition that the pump beam is of Gaussian profile, the intensity distribution of SBS spot is changed from quasi-Gaussian to Gaussian profile when the pump energy increases.

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