Research on mechanism and application of effect of adjustment errors in aspheric surface stitching interferometry

Abstract

Due to the existence of imprecise fitting of subapertures’ overlap zone, the accumulation of adjustment errors is significant during the measurement of aspheric surface by stitching interferometry. Theoretical analysis indicates that the effect and the appearance of three-direction adjustment errors accords with that of Seidel aberration, of which the axial error leads defocus, third-order spherical aberration and higher-order errors of wave front distribution. Based on the analysis we have made, a correction model has been established, and the estimated values of adjustment errors have been acquired. By correcting the higher-order aberration in the model, fitting precision of subapertures’ overlap zone can be improved. Experiment for comparison shows that, after fitting, the value of both residual error and uncertainty of measurement become smaller than those values obtained by traditional correction method of three-direction adjustment error, which proves that the stitching precision of proposed method is higher.