Liu Fengwei, Wu Yongqian, Wu Fan
Opt Express. 2015 Jul 27;23(15):19932-46. doi: 10.1364/OE.23.019932.
We propose a novel phase shifting interferometry from two normalized interferograms with random tilt phase-shift. The determination of tilt phase-shift is performed by extracting the tilted phase-shift plane from the phase difference of two normalized interferograms, and with the calculated tilt phase-shift value the phase distribution can be retrieved from the two normalized frames. By analyzing the distribution of phase difference and utilizing special points fitting method, the tilted phase-shift plane is extracted in three different cases, which relate to different magnitudes of tilts. Proposed method has been applied to simulations and experiments successfully and the satisfactory results manifest that proposed method is of high accuracy and high speed compared with the three step iterative method. Additionally, both open and closed fringe can be analyzed with proposed method. What's more, it cannot only eliminate the small tilt-shift error caused by slight vibration in phase-shifting interferometry, but also detect the large tilt phase-shift in phase-tilting interferometry. Thus, it will relaxes the requirements on the accuracy of phase shifter, and the costly phase shifter may even be useless by applying proposed method in high amplitude vibrated circumstance to achieve high-precision analysis.
我们提出了一种基于具有随机倾斜相移的两个归一化干涉图的新型相移干涉测量方法。倾斜相移的确定是通过从两个归一化干涉图的相位差中提取倾斜相移平面来进行的，利用计算得到的倾斜相移值，可以从这两个归一化帧中恢复相位分布。通过分析相位差的分布并采用特殊点拟合方法，在三种不同情况下提取倾斜相移平面，这三种情况与不同的倾斜幅度相关。所提出的方法已成功应用于模拟和实验，令人满意的结果表明，与三步迭代法相比，该方法具有高精度和高速度。此外，所提出的方法可以分析开放条纹和封闭条纹。而且，它不仅可以消除相移干涉测量中由轻微振动引起的小倾斜偏移误差，还可以检测相倾斜干涉测量中的大倾斜相移。因此，它将放宽对相移器精度的要求，在高振幅振动环境中应用所提出的方法以实现高精度分析时，昂贵的相移器甚至可能无用。
