应用光学, 2013, 34 (5): 802, 网络出版: 2013-12-04
基于二维傅里叶变换的单帧干涉图相位提取方法
Phase extraction for single frame interferogram based on 2D Fourier transform
摘要
针对大口径光学元件干涉测试过程中, 测试装置和干涉腔长较大, 气流扰动和环境振动对移相测试过程产生影响等问题, 采用一种基于二维傅里叶变换的单帧干涉图处理方法, 只需要对一幅空间载频干涉条纹图进行处理即可获得待测相位, 具有抗振测试的优点。对该方法的基本原理和算法过程进行分析, 并对近红外大口径移相平面干涉仪中600 mm口径的光学平晶进行了面形测试。实验结果表明: 采用该方法所得波面峰谷值(PV)为0.112λ, 波面均方根值(RMS)为0.014λ, 与移相算法所得波面数据相比, 波面峰谷值偏差不到(1/500)λ; 波面均方根值(RMS) 偏差几乎为零。
Abstract
For the interferometric testing of optical elements with large aperture, due to large testing device and interferometric cavity length, the process of phase-shifting interferometry was affected by airflow disturbance and environmental vibration. In order to overcome the above factors, a single interferogram processing method based on two-dimensional fast Fourier transform(FFT) was proposed. This method only required one single spatial carrier fringe pattern to obtain the phase, which had the advantage of anti-vibration testing. The basic principle and the process of algorithm were analyzed, and the optical element with 600 mm large aperture in the near-infrared phase-shifting Fizeau interferometer was tested. Experimental results show that the peak-to-valley (PV) value and root mean square (RMS) value of the wavefront obtained by FFT method are 0.112 λ and 0.014 λ respectively, compared with the results obtained by phase-shifting method, there are a difference less tham (1/500)λ in PV and almost zero difference in RMS.
单小琴, 朱日宏, 李建欣. 基于二维傅里叶变换的单帧干涉图相位提取方法[J]. 应用光学, 2013, 34(5): 802. SHAN Xiao-qin, ZHU Ri-hong, LI Jian-xin. Phase extraction for single frame interferogram based on 2D Fourier transform[J]. Journal of Applied Optics, 2013, 34(5): 802.