The accurate method for removing misalignment errors from testing rectangular optics

摘要

The limitations of current interferogram reduction software with Zernike polynomials in analyzing rectangular inter-ferogram are illuminated. The Zernike polynomials are no longer orthogonal over an rectangular region and have no explicit physical meanings. The reasonable mathematical model for removing translation errors is established based on least squares fitting. The experiment is carried on with a 500mm 160mm aspherical mirror by nullcompensation. The misalignment errors can be eliminated from the original phase distribution exactly, thus the accurate surface map is gained. It provides a guarantee for the superprecision fabrication.