Misalignment Model Used In Three-Position Absolute Measurement

Interferometric measurement, as dominating testing methods, is widely used in the field of optical measurement. Conventional interferometer subjects to many factors which make the measurement accuracy between gamma/10 and gamma/20, so it's difficult to meet the surface testing requirements of high accuracy. Thus the three-position absolute measurement technique is used to remove the errors which are introduced by reference surface and interferometer itself. The detailed process and experiment of three-position absolute measurement are given. A misalignment model by rigid body theory is presented, and the corresponding influence on interferometric measurement result is analyzed. The simulation results by the presented model are compared with that of Zemax software. By comparing both simulation results, it confirms the feasibility of the misalignment model.