| 摘要 |
An optical element having an optical surface (12; 103), which optical surface has an actual shape, the actual shape deviating from a desired shape by maximum 0.2 nm, wherein the desired shape is either: a free-form surface having a deviation from its best-fitting sphere of at least 5 μm or a substantially rotationally symmetrical surface having a deviation from its best-fitting sphere of at least 0.5 mm. |
