| 摘要 |
PURPOSE: To enable a precise absolute measurement of a plane by using the plane a flatness of which is to be inspected as an interferometer mirror, and storing wave front interferences of the plane. CONSTITUTION: A laser L generates parallel light beams. A width of the beams is enlarged by a telescope T. The beams are guided to a measurement beam path M and a reference beam path RF by a beam splitter S. A first, a second interferometer mirrors I, H return the reference beam path RF and measurement beam path M to original directions. The returned paths are guided to a camera sensor K by the splitter S. The sensor K detects a three-dimensionally resolved interference image of reference beams by the measurement beams, namely, an interferogram. The mirror I in the beam path RF is turned a slight angleεfrom a vertical direction. Since an actual plane always has a heightwise deviation, three-dimensional wave front interferences are unavoidable which, however, are calculated by a calculator R according to a three-column algorithm.
|
