Tavassoly M Taghi, Samavati Katayoon
Appl Opt. 2014 Oct 1;53(28):6612-8. doi: 10.1364/AO.53.006612.
In this report we present formulation of moiré fringes that are formed by superimposing two basically similar linear amplitude gratings but with slowly varying parameters. We show that the resulting fringes, in general, in the first approximation satisfy quadratic functions, and they represent phase contours in the neighborhood of the phase singularity associated with the superposition of two exactly similar linear gratings with parallel rulings. By fabricating linear gratings with slowly varying parameters and superimposing them on similar gratings with fixed parameters, it is verified that quadratic functions fit satisfactorily on the traces of the resulting moiré fringes, and the deflections in the parameters are deduced from the fitting. Having in mind that changes in many physical quantities are convertible into the changes of grating parameters, the technique provides a useful means for accurate and reliable studies of many physical effects.
在本报告中，我们阐述了通过叠加两个基本相似但参数缓慢变化的线性振幅光栅所形成的莫尔条纹的公式。我们表明，一般来说，所产生的条纹在一阶近似下满足二次函数，并且它们代表了与两个具有平行条纹的完全相似的线性光栅叠加相关的相位奇点附近的相位轮廓。通过制造参数缓慢变化的线性光栅并将它们叠加在具有固定参数的相似光栅上，验证了二次函数能很好地拟合所产生的莫尔条纹的轨迹，并且从拟合中推导出参数的偏差。考虑到许多物理量的变化可以转换为光栅参数的变化，该技术为准确可靠地研究许多物理效应提供了一种有用的手段。
