根据数字全息干涉术的基本原理,利用CCD分别记录物场状态变化前后的无透镜傅里叶变换全息图,通过数值再现分别得到不同状态下物场的复振幅分布,从而直接得到不同状态下物场间的干涉条纹图样。如果该物场是由板状试样的离面弯曲引起的,则通过测量干涉条纹图样中相同相位条纹的渐近线之间的夹角,即可确定出材料的泊松比。实验证明该方法简单易行,尤其适合对光学粗糙表面、小泊松比或小尺寸的试样进行全场测量,测量结果具有良好的重复性,较高的灵敏度和精度。

Base on the principle of digital holographic interferometry, two lensless Fourier transform holograms representing two different deformation states of object field are captured by CCD. Then the numerical reconstruction of digital holograms is implemented respectively to acquire the complex amplitude of object waves, and the interference phase difference is determined by subtracting the phases of the different states. According to the pure bending theory in elastic mechanics, the Poisson′s ratio is derived numerically from the angle between the asymptotic lines of the fringes of equal phase, which are caused from homogeneous deformation and reconstructed by digital holographic interferometry. This method for determination of Poisson′s ratio of material in the full-access performance by experiment is simple and easy to operate, especially suitable for material with rough surface, low value Poisson′s ratio and small size.