Error analysis of absolute testing based on even-odd functions method

Abstract

Recently most of modern absolute measurement rotation the flats or spheres in the interferometer. We review traditional absolute testing of flats methods and emphasize the method of even and odd functions. The rotation of the lens can lead to some errors such as angle rotation error, center excursion error and other coordinate system motion error. We analyze the errors by using Zernike polynomial. The flat or sphere can be expressed as Zernike polynomial which can also be divided into even-odd, odd-even, even-even and odd-odd functions. We can use 36 Zernike polynomials to generate 3 plats A, B, C. Then the six measurements can be generated from the three plats. For the angle rotation error, we can simulate the angle error distribution and substitute in the systems. According the error distribution we can change the arithmetic to improve the measurement accuracy. The results of errors analyzed by means of Matlab are shown that we can change the arithmetic according the coordinate direction motion errors which can be detected to improve the accuracy. The analysis results can also be used in other interferometer systems which have the motion of the coordinate system.