Ultra-long curvature radius control technology of spherical optical element during full aperture polishing

Automatic measurement of single points schema by coordinate measuring machine(CMM) is used to measure the Ultra-Long curvature radius of spherical optical element. The removal quantity of each measuring point can be calculated through contrasting the measure value and the theoretical value. A removal model of spherical optical element polishing is established based on Preston equation, and the required machining parameters are predicted by removal simulation in MATLAB. A processing test on a fused silicon with an aperture of 440mm×440mm was performed and the result shows that the model is effective in Ultra-Long curvature radius control of spherical optical element during full aperture polishing.