Gwangju scanning device and radiation detector

摘要

A device for scanning a surface is described, which device comprises a radiation source (5), a transparent plate (18) provided with a grating (17) having two grating structures, and an objective lens (7) for focusing radiation on the surface (3). And a detection system 12 for converting the radiation reflected by the surface into electrical signals. The first grating structure of the grating 17 is intended to form two side-beams 21, 22 from the radiation beam 6. By providing the second grating structure, the monitor beam 13 is obtained by reflecting from the radiation beam 6. This monitor beam is directed to the monitor detector 14 which generates an electrical signal, controlling the radiation power of the radiation source 5.