Measurement of scanning prism by laser Haidinger interference

It is usually difficult to reach an expected testing accuracy using general methods to measure the scanning prism. So this paper puts forward a new method of testing the angular error and pyramidal error of the scanning prism by the Haidinger interference. The relative formulas are deduced, the testing method and instrument are presented in the paper. We also analyzed the testing accuracy. The actual testing accuracy of this method is about 0.5 inches. It is one of the best methods with high accuracy at present. In addition, this method can be used to estimate the surface deviation according to the interferogram. This method belongs to common path interference. The fringe is stable and reliable.