Effect on the measurement precision of a multi-pass heterodyne interferometer by an acceleration and compensation method

Abstract

To reduce the theoretical measurement error caused by a high acceleration in fast ultra-precision laser heterodyne interferometry, a model is proposed. This model is about how the displacement measurement precision is affected by the acceleration of the measuring prism in a multi-pass heterodyne interferometer. In the model, the integrals of Nv 2 /c and Nax/c are added on the basis of a conventional heterodyne interferometer model. It shows, that in the conventional model the measurement error increases with increasing measurement acceleration. An error compensation method is proposed, which uses numerical integration to obtain the real time speed and acceleration. Corrected data can be acquired by using an error correction formula. Simulation results show, that the measurement error can be reduced by this method from 10nm to 0.03nm when the displacement of the measuring prism is 500mm and the uniform acceleration of the measuring prism of a double pass interferometer equals g.