To solve the coherent noise problem of an interference image, the method of a rotating diffuser was adopted to change the coherence of a beam to reduce the noise of the interference system. The relationship between the speed of the diffuser and the signal-to-noise ratio (SNR) of the fringe contrast system was simulated to obtain the diffuser control parameters needed for the best interference fringe state. The fringe contrast of each image and the SNR of the system were analyzed. The results showed that the increased speed of the diffuser reduced the contrast of the interference image to a certain extent, but the increased speed also effectively improved the SNR and facilitated the subsequent interference image processing. Due to the coherent noise in the interferometric system, the method of the rotated diffuser reduced the coherence of the light beam to suppress the noise of the interference image. By analyzing the coherent noise reduction characteristics of the rotated diffuser with different surface roughnesses, the relationship between the surface roughness and the noise contrast for different rotation speeds was simulated, and the effective roughness range with the noise reduction effect was selected. A noise reduction system was built based on Fizeau interference, and the noise contrast of the interference image was collected and calculated. The effective range of σ_h/λ was 0.2–0.5 when the rotation speed was 10 r/s, while the effective range of σ_h/λ was 0.4–0.6 when the rotation speed was 100 r/s. The experimental results showed that the surface roughness and wavelength ratio σ_h/λ of the rotated diffuser increased when the noise contrast tended toward 1, but the effective range of the surface roughness decreased with the increase of the rotational speed of the diffuser.

中文翻译：

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用Fizeau干涉法分析扩散器的降噪特性

为了解决干涉图像的相干噪声问题，采用了旋转扩散器的方法来改变光束的相干性，以减少干涉系统的噪声。仿真扩散器的速度和条纹对比系统的信噪比（SNR）之间的关系，以获得最佳干涉条纹状态所需的扩散器控制参数。分析了每个图像的条纹对比度和系统的信噪比。结果表明，漫射器速度的提高在一定程度上降低了干涉图像的对比度，但提高的速度也有效地提高了信噪比，促进了后续干涉图像的处理。由于干涉仪系统中的相干噪声，旋转漫射器的方法降低了光束的相干性以抑制干涉图像的噪声。通过分析不同表面粗糙度的旋转扩散器的相干降噪特性，模拟了不同转速下表面粗糙度与噪声对比度之间的关系，选择了具有降噪效果的有效粗糙度范围。基于菲索干扰建立了降噪系统，收集并计算了干扰图像的噪声对比度。有效范围 模拟了不同转速下表面粗糙度与噪声对比度之间的关系，并选择了具有降噪效果的有效粗糙度范围。基于菲索干扰建立了降噪系统，收集并计算了干扰图像的噪声对比度。有效范围 模拟了不同转速下表面粗糙度与噪声对比度之间的关系，并选择了具有降噪效果的有效粗糙度范围。基于菲索干扰建立了降噪系统，收集并计算了干扰图像的噪声对比度。有效范围σ _ħ / λ为0.2-0.5时的旋转速度为10转/ s，而有效范围σ _ħ / λ是0.4〜0.6时的旋转速度为100转/秒。实验结果表明，表面粗糙度和波长比σ _ħ / λ时，噪声相反朝向1趋于旋转扩散器的增加，但表面粗糙度的有效范围与扩散器的旋转速度的增加而降低。