Jacquot P, Rastogi P K
Appl Opt. 1979 Jun 15;18(12):2022-32. doi: 10.1364/AO.18.002022.
In line with the current interest in speckle motion in free-space propagation, it is proposed to investigate new aspects of the induced speckle motion due to rigid-body movements of a model using as a starting point the well-known concept of homology, first stated in holographic interferometry, the importance of which has only recently been realized in speckle metrology. At the outset, stating the homology conditions leads to a general expression relating the speckle shift to the geometrical parameters at the recording and to the six degrees of movement of the object surface. The expression presented in this explicit form is found to be true for both opaque and thin transparent diffusing models and for different conditions of illumination and observation. The study is then extended to (1) when the object is at rest, subjecting the illuminating source to a small displacement and (2) when the wavelength of the illuminating beam is changed between the two exposures. The case of the rigid-body displacement of the object is experimentally verified and the results are found to be in good agreement with theory. The viability of the method to make measurements is assessed, several applications are envisaged, and some advantages are pointed out.
鉴于当前对自由空间传播中散斑运动的关注，本文提出以全息干涉测量中首次提出的同调性这一著名概念为出发点，研究模型刚体运动引起的散斑运动的新方面，该概念的重要性直到最近才在散斑计量学中得到认识。首先，阐述同调条件会得出一个将散斑位移与记录时的几何参数以及物体表面的六个运动自由度相关联的通用表达式。以这种明确形式给出的表达式被发现对于不透明和薄透明漫射模型以及不同的照明和观察条件均成立。然后，研究扩展到：（1）物体静止时，使照明源发生小位移；（2）两次曝光之间改变照明光束的波长。对物体刚体位移的情况进行了实验验证，结果与理论高度吻合。评估了该测量方法的可行性，设想了几种应用，并指出了一些优点。
