Research On The Key Technologies Of Large Plane Measurement Based On The Phase-shifting Interferometry

Inertial Confinement Fusion(ICF) is an effective way for human beings to solve the global energy crisis. The key of ICF system performance is the processing quality of large plane in ICF driver system. The new requirements have been proposed in processing and testing of large plane. In particular, the measurement of large plane has become more and more important.The key technology of large plane measurement based on the phase-shifting interferometry is researched in our subject. A more precise plane was used as a reference flat when a precision plane is measured by the phase-shifting interferometry. Therefore the absolute measurement need to be introduced to calibrate the reference surface error and systematic error in the measurement of large plane with high precision.This paper is a research on absolute measurement. The three-flat test was an important interferometry for absolute measurement of high precision. And the one-dimensional flatness information in Y axis of three planes were tested by the traditional three-flat test, which couldn't achieved the measurement of the flatness information in 3D. In this paper, an improved three-flat test was studied for the limitation of traditional method. The 3D of the whole flatness information has been measured using this method, and the reference surface error and systematic error in the measurement have been demarcated.Three standard lens can be measured using the improved three-flat test through the modified experiment equipment and the preparation data processing procedure.The measurement results of this improved method and the results of direct measurement by the "three-flats" in ZYGO interferometer are compared and analyzed, so the feasibility and effectiveness of improved method has been verified. And the instructive conclusions for this method use in the follow-up study of the project were obtained.