| 摘要 |
The chromatic aberration correcting device has two multipole lenses for generating the quadrupole fields, while each of the two relay lenses has a focal length (f). The multipole lenses are arranged on the opposite sides of the relay lenses that are separated by a distance of 2f. The distance between the former multipole lens and the former relay lens is f-delta1, while the distance between the latter relay lens and the latter multipole lens is f-delta2. An auxiliary lens is arranged between the relay lenses. The optical axis is measured along the length between the multipole lenses. An independent claim is included for a method for controlling a chromatic aberration correcting device. |
