| 摘要 |
PURPOSE:To manufacture an optional optical aspherical surface, by shielding a material to be worked from an ion beam with a mask, and subjecting the same to ion milling while rotating the work. CONSTITUTION:An aperture 6 is opened to a mask 2, and the aperture 6 is opened in proportional to a desired ion milling depth at the point of a distance (r) from the center 7 of the mask 2. The material to be worked 3 is subjected to ion milling for the time calculated from an ion milling speed while the material 3 is rotated under the mask 2, whereby an aspherical surface having a desired distribution t(r) of the ion milling depth is manufactured. |
