Experiment analysis of absolute flatness testing

Abstract

Result of the testing contain the reference surface errors and test surface errors in the high-accuracy Phase shifting interferometer which test the relative phase between the two surface. The test accuracy can be achieved by removing the error of reference surface. In this case, one of body of so-called absolute testing must be used which can test the systematic errors, including the reference surface, of the instrument to be used to improve the test accuracy. The accuracy of the interferometer needs different methods to determine in the high accuracy testing. Even-Odd function method and rotation shear method is introduced in this paper. We use the Zygo interferometer Verifire Asphere to do the experiment and analyze the errors caused by data processing and interpolation. The result of the experiment can determine the accuracy of our arithmetic.