Single-shot reflective shearing point diffraction interferometer for wavefront measurements.
Single-shot reflective shearing point diffraction interferometer for wavefront measurements.
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DOI：
10.1364/ao.54.006155
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发表时间：
2015-07
期刊：
影响因子：
1.9
通讯作者：
Wenhua Zhu;Lei Chen;C. Gu;Jun Wan;Donghui Zheng
中科院分区：
文献类型：
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作者：
Wenhua Zhu;Lei Chen;C. Gu;Jun Wan;Donghui Zheng
设计了单镜头反射剪切点衍射干涉仪（S-SRSPDI），用于大口径动态波前测量。PDI集成在小基板上，采用适当设计的薄膜。待测波前分别被基片的前后表面反射，生成高线性载波频率的干涉图，利用傅里叶变换算法重构波前。本文推导了干涉图强度分布的解析公式。讨论了与条纹载波频率有关的参数。通过对反射偏振效应的分析，提出了优化干涉图对比度的方法。此外，通过设计合适的阻挡膜，可以去除干涉图中的杂散条纹。采用S-SRSPDI对直径为400 mm的动态波前进行检测。实测的像差与剪切法得到的像差吻合较好，验证了S-SRSPDI是大口径动态波前测量的有力工具。
A single-shot reflective shearing point diffraction interferometer (S-SRSPDI) is designed for large-aperture dynamic wavefront measurements. The PDI is integrated on the small substrate with properly designed thin film. The wavefront under test is reflected by the front and rear surfaces of the substrate respectively to generate an interferogram with high linear-carrier frequency, which is used to reconstruct the wavefront by means of the Fourier transform algorithm. In this paper, the analytic formula of intensity distribution of the interferogram is derived. The parameters related with the carrier frequency of fringes are discussed. The method to optimize the contrast of the interferogram is proposed by analyzing the reflective polarization effects. In addition, the spurious fringes of the interferogram are removed by the proper designed blocking film. S-SRSPDI was applied to detect the dynamic wavefront with a diameter of 400 mm. The measured aberrations are in good agreement with those obtained by the shearing method, which verifies that the proposed S-SRSPDI is a powerful tool for large-aperture dynamic wavefront measurements.