Influence and optimization of CCOS processing path to surface errors

Abstract

Computer Controlled Optical Surfacing (CCOS) technology is one of the most commonly method in optical manufacture. Though CCOS is efficient, there is an unavoidable disadvantage. Middle and high spatial frequency errors, also called the ripple errors, will be left over on the optical surface. This kind of error may have a serious impact on the performance of the optical system. Focus on the grating path, the quantitative relationship between step size and ripple errors is obtained. In order to effectively restrain the ripple errors, a locally random path with Gaussian distribution is proposed. The surface figures that achieved by two different tool paths have been simulated. The results prove that the locally random path can re-distribute the remove amount of the surface. Therefore, the regular remove distribution caused by grating path disappears. It means that the specific surface errors can be restrained effectively.