中国激光, 2018, 45 (6): 0604001, 网络出版: 2018-07-05
基于白光干涉频域分析的高精度表面形貌测量 下载: 975次
High-Resolution Surface Topography Measurement Based on Frequency-Domain Analysis in White Light Interferometry
测量 空间频域 白光干涉 2π模糊; 相干信息 相位突变 measurement spatial frequency domain white-light interference 2π ambiguity; coherence information phase jump
摘要
提出了一种基于空间频域分析的白光干涉测量算法,该算法通过消除相位信息中的2π模糊来实现高精度的表面形貌测量。在频域分析中可以同时提取样品的相干形貌和相位形貌。相干形貌虽然不受2π模糊的影响,但是包含测量误差,精度较低。相位形貌虽然能够实现较高精度的表面形貌测量,但存在2π模糊问题。因此采用相干信息与相位信息相结合的方式来消除相位信息中的2π模糊。此外,针对由背景噪声和光源扰动所引起的局部相位突变,提出了相邻像素点差分分析方法,有效消除了局部相位突变,从而提高了测量的稳定性。该方法不需要复杂的计算,工作效率较高。分别从理论和实验两个方面进行分析,以验证提出方法的有效性。
Abstract
A white-light interference algorithm based on spatial frequency-domain analysis is described, which permits a high-resolution surface measurement by removing 2π ambiguity contained in phase information. In the frequency domain analysis, we can extract the coherence and phase profiles simultaneously, where the coherence profile is free of 2π ambiguity but contains the measurement errors caused by background noises, while the phase profile is precisely the opposite. By combining the coherence and phase information, we remove the 2π ambiguity contained in phase information successfully. In addition, a differential analysis method between adjacent pixels is adopted to deal with the local 2π phase-jump errors, which are caused by the background noises and the light source fluctuations. This technique is highly efficient since it does not require enormous computation. Both theories and experiments are elaborated in detail to verify the validity and stability of this method.
邓钦元, 唐燕, 周毅, 杨勇, 胡松. 基于白光干涉频域分析的高精度表面形貌测量[J]. 中国激光, 2018, 45(6): 0604001. Qinyuan Deng, Yan Tang, Yi Zhou, Yong Yang, Song Hu. High-Resolution Surface Topography Measurement Based on Frequency-Domain Analysis in White Light Interferometry[J]. Chinese Journal of Lasers, 2018, 45(6): 0604001.