散斑剪切干涉条纹特性的实验研究

LABORATORY INVESTIGATION OF THE FRINGE CHARACTERISTICS OF SPECKLE- SHEARING INTERFEROMETRY

本文通过位移位相存在的真实性实验、小孔滤波的必要性实验、位移梯度的解相关性实验,证实了散斑剪切于涉术的条纹是由物体变形所引起的“位移位相”和“位移微分位相”以及由位移和位移微分共同决定的“附加位相”之和的余弦条纹。实验证实这种余弦条纹的分布,随着滤波孔的位置而变化,它的衬比随着位移和位移梯度的增大而下降。特别是,当在象面上一点相遇的两个物点的象面散斑位移之差的模值大于散斑的直径时,两者相遇的象点上的条纹消失。

In this paper the fringe characteristics of speckle-shearing interferometry is investigated by the method of statistical optics. The results show: Under the circumstances of general deformation, the fringe of speckle-shearing interferometry is a cosine fringe of the 'displacement phase' (namely, the fringe phase of speckle photography), the 'displacement-differential phase' (namely, the fringe phase of Hung's speckle-shearing interferometry), and a additional phase that is determined by object deformation. The distribution of this cosine frinage changes with the position of the filtering aperture, and its contrast sinks with the increase of displacement and displacement-differential Particularly, the fringes at a image point will disappear when the modalus of the speckle-displacement difference in the image plane of two object points that meet at an image point is greater than the speckle diameter.