The swing arm profilometer (SAP) has been playing a very important role in testing large aspheric optics. As one of most significant error sources that affects the test accuracy, misalignment error leads to low-order errors such as aspherical aberrations and coma apart from power. In order to analyze the effect of misalignment errors, the relation between alignment parameters and test results of axisymmetric optics is presented. Analytical solutions of SAP system errors from tested mirror misalignment, arm length L deviation, tilt-angle θ deviation, air-table spin error, and air-table misalignment are derived, respectively; and misalignment tolerance is given to guide surface measurement. In addition, experiments on a 2-m diameter parabolic mirror are demonstrated to verify the model; according to the error budget, we achieve the SAP test for low-order errors except power with accuracy of 0.1 μm root-mean-square.
CCOS (Computer Controlled Optical Surfacing) is one of the most important method to manufacture optical surface.
By controlling the dwell time of a polishing tool on the mirror we can get the desired material removal. As the optical
surface becoming larger, traditional CCOS method can’t meet the demand that manufacturing the mirror in higher
efficiency and precision. This paper presents a new method using multi-mode optimization. By calculate the dwell time
map of different tool in one optimization cycle, the larger tool and the small one have complementary advantages and
obtain a global optimization for multi tool and multi-processing cycles. To calculate the dwell time of different tool at the
same time we use multi-mode dwell time algorithm that based on matrix calculation. With this algorithm we did
simulation experiment, the result shows using multi-mode optimization algorithm can improve the efficiency
maintaining good precision.