Simulation and error analysis of non-null interferometry for measuring high-order aspheric surface parameter errors

Aspheric surfaces are widely used in advanced optical instrument. Measuring aspheric surface parameter errors (SPEs) in high accuracy is of vital importance in manufacturing and aligning optical aspheric surfaces. A simulation to prove the effectiveness and accuracy of an interferometric measurement method for high-order aspheric SPEs is carried out based on the ideal situation that there is no error of the BCD. The relative accuracy of vertex radius of curvature error, conic constant error and fourth order aspheric coefficient error can reach 5.58×10-8 %, 1.36×10-4 % and 0.02%. The influence of the BCD error is analyzed to prove the feasibility of this method and provide a theoretical guidance for real measurement configurations. This method can measure all kinds of aspheric surface parameter errors mentioned above simultaneously in high accuracy.