Rajshekhar Gannavarpu, Gorthi Sai Siva, Rastogi Pramod
Applied Computing and Mechanics Laboratory, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
Appl Opt. 2011 Jul 20;50(21):4189-97. doi: 10.1364/AO.50.004189.
This paper proposes an elegant technique for the simultaneous measurement of in-plane and out-of-plane displacements of a deformed object in digital holographic interferometry. The measurement relies on simultaneously illuminating the object from multiple directions and using a single reference beam to interfere with the scattered object beams on the CCD plane. Numerical reconstruction provides the complex object wave-fields or complex amplitudes corresponding to prior and postdeformation states of the object. These complex amplitudes are used to generate the complex reconstructed interference field whose real part constitutes a moiré interference fringe pattern. Moiré fringes encode information about multiple phases which are extracted by introducing a spatial carrier in one of the object beams and subsequently using a Fourier transform operation. The information about the in-plane and out-of-plane displacements is then ascertained from the estimated multiple phases using sensitivity vectors of the optical configuration.
本文提出了一种在数字全息干涉测量中同时测量变形物体面内和面外位移的精妙技术。该测量方法依赖于从多个方向同时照射物体，并使用单个参考光束在电荷耦合器件（CCD）平面上与散射的物体光束发生干涉。数值重建提供了与物体变形前和变形后状态相对应的复物体波场或复振幅。这些复振幅用于生成复重建干涉场，其实部构成莫尔干涉条纹图案。莫尔条纹编码了关于多个相位的信息，通过在其中一束物体光束中引入空间载波并随后进行傅里叶变换操作来提取这些信息。然后，利用光学配置中的灵敏度矢量，从估计的多个相位中确定面内和面外位移的信息。
