| 摘要 |
The device is intended to provide, for a plane object having a spatial periodicity along at least one direction, a diffraction image with a magnification very different from unity. It comprises a monochromatic coherent point source illuminating the object. In order to correct the fourth-order aberrations, an optical element 18 is interposed between the source S and the object 14. This element will generally be formed by a parallel-faced plate 18 of suitable thickness and index. The device can especially be used in metrology. <IMAGE> |
