研制点衍射干涉仪时,小孔的形貌和装调误差会对衍射波前质量产生影响,故本文研究了采用相位复原对小孔衍射波前质量进行测评的方法。设计并搭建了衍射波前测试装置,对光纤衍射波前进行了测评实验。为了验证测试方法的有效性,分别对采集的衍射图像与重构的衍射图像,以及测试获得的振幅分布与理论计算获得的振幅分布进行了对比。结果显示。采集图像与重构图像之间的差异为0.32%,验证了采用相位复原技术进行衍射波前测试方法的有效性。同时,对干涉方法测量与相位复原结果进行了对比,二者差异仅为0.001 4λ RMS。

As the morphology of an ultra small aperture and the assembling error will affect the quality of wavefront diffraction in development of a point diffraction interferometer, this paper explores an evaluating method for wavefront diffracted quality from the ultra small aperture based on the phase retrieval. The testing equipments for wavefront diffraction was designed and the evaluating testing experiment for the wavefront diffraction were performed. To verify the effectiveness of the method based on the phase retrieval, the captured and reconstructed images were compared, and the obtained amplitudes with the theoretical calculation and experimental test were also analyzed. The results show that the difference between captured images and reconstructed images is only 0.32%, which verifies that the proposed method is feasibility. Moreover, the interferometric measurement result was compared with that of the phase retrieval proposed in this paper, and the results show that the difference is only 0.001 4λ RMS(Root Mean Square).