基于菲索干涉的变频相移技术, 提出一种分步相移标定方法.生成n组t步相移干涉图,每步相移为π/2;将每步的n组干涉图分别与初始干涉图做相乘和傅里叶变换运算, 在此基础上构建每步相移的误差函数;通过求取误差函数极值点来实现对每步相移值的准确标定.结果表明, 该标定方法的标定准确度优于传统标定方法, 且标定准确度提高了2~3个数量级.该方法不仅避免了传统相移标定中存在的随机误差, 也彻底消除了累积误差.

Based on the wavelength tuning phase-shifting technology in Fizeau interferometer, a phase-shifting calibration method with step by step was presented. First, the n groups interferograms with t step were generatd , the step is π/2. Then, the error function for each step was built through the origin interferogram multiplied by n group of each step separately and making Fourier transform. Finally, the precision calibration was realized by calculating the extreme point of error function curve. The experiment results show that, the calibrating precision is better than the traditional ones and the calibration accuracy is up to 2 or 3 orders to compare with the traditional method. This new method not only avoids the random error, but also eliminates the accumulated error completely.