摘要
针对移相干涉术易受振动、气流等扰动影响的问题,提出一种时频域双重分析法的抗干扰移相干涉测量方法。采集一系列连续移相的干涉图,通过对干涉图上各点时序光强进行频谱的宽带滤波提取到干涉图采集过程中真实的相位变化,对时序的相位变化信息进行线性统计得到各点初始相位的计算值。在干涉图帧数足够多的情况下,线性统计后随机噪声的影响趋于零,环境振动等非随机性扰动的影响被归结为一个与像素坐标无关的值从而不影响波面形状,因此不影响面形测量精度。通过仿真实验验证了该方法的可行性。将该方法应用在普通实验室条件下的机械式移相干涉测量系统中进行实际的测量,结果与同一个被测件在FISBA干涉仪中的测量结果很好地吻合,验证了该方法的抗干扰能力。
Because interferometry is highly sensitive to disturbance such as vibration and air flow, a time-and- frequency domain （TFD） interferometry is proposed. A large number of continuous phase-shifting interferograms are captured. A distorted series of phase variety during fringe capturing is obtained through wide bandwidth filter to the spectrum of intensity series from a particular pixel, and then a linear statistic of it gives the measuring result of initial phase. With a large enough number of frames, the linear statistic efficiently reduces random noises to zero. And influences introduced by other non-random disturbances are astringed into a value which is independent of the index of pixels and therefore does not influence the shape of the whole wavefront. A simulation confirms the feasibility of the TFD method, and an experiment is carried out applying TFD method in a mechanical phase-shifting interferometric system fixed in a normal laboratory environment. The result prettily matches that from a FISBA interferometer, which verifies the anti-noise ability of TFD method.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2011年第11期146-150,共5页
Acta Optica Sinica
基金
国家自然科学基金(60578053)资助课题
关键词
测量
移相干涉术
抗扰动
时频域双重分析方法
measurement
phase-shifting interferometry
anti disturbance
time-and-frequency domain method
