使用最小二乘迭代相移方法测量透明元件

Measure transparent elements using least squares iterative phase shift method

为了更精确地测量透明平板前后两个面的面形相位发布,提出了一种基于最小二乘迭代的相移算法。通过一次最小二乘相移算法后,可以得到相应的透明平板面形图,但是由于初始得到的相位值存在误差,因此得到的面形图精度并不会很高。因此需要通过得到的面形图推导出准确的相位值,本算法通过最小二乘发多次迭代的方法,计算出较准确的初始相移值。对该方法进行仿真实验后,可知此算法的测量精度较高且抗噪能力比较好,仿真得到面形图的PV值与RMS值误差值均小于0.006λ。在实际测量结果中,得到测量结果的PV值误差小于0.09λ,RMS误差小于0.02λ。测量到的面形与物体真实面形接近,测量精度较高。

In order to measure the surface phase of the front and back of the transparent plate more accurately,a phase shift algorithm based on least squares iteration is proposed.After a least squares phase shift algorithm,the corresponding transparent flat surface pattern can be obtained,but the accuracy of the obtained surface map is not high because there is an error in the initial phase value.Therefore,it is necessary to derive the accurate phase value from the obtained surface map.The algorithm calculates the more accurate initial phase shift value by the method of least squares and multiple iterations.After the simulation experiment of the method,it is known that the measurement accuracy of this algorithm is high and the anti-noise ability is better.The error of the PV value and RMS value of the surface map is less than 0.006λ.In actual measurement results,the PV error of the measurement result is less than 0.09λ,and the RMS error is less than 0.02λ.The measured shape is close to the true shape of the object,and the measurement accuracy is high.