| 摘要 |
<p>Disclosed is a phase-shifting diffraction grating interferometer using diffraction grating. When a light source incident to the diffraction grating is resolved into several diffraction lights, one of them having a diffraction element is selected as a reference light, and other part having the diffraction element or another light having other diffraction element is selected as a light directing to an object to be measured. The light directing to the object to be measured is reflected from the object and is incident to the diffraction grating and then diffracted, and object lights made by the diffraction generates the reference light and an interference pattern. When the diffraction grating is moved in a longitudinal direction, the object light or the reference light is phase-shifted, a number of interference patterns are obtained, and the interference patterns are analyzed to obtain a shape of the measured object. The present invention relates to an improved diffraction grating interferometer capable of being used in an optical metrology field, and the interferometer includes interferometers of various types, which is capable of measuring various kinds of objects to be measured. The phase-shifting diffraction grating interferometer includes a light source part, a beam splitter or a light direction controller, a phase-shifting generator, an interference pattern generator, an interference pattern obtaining part, a central processing unit and a result displaying part. The light source part includes a light source and a lens, a pinhole, a collimator or an optical fiber. The optical elements can be removed according to characteristics of this system or replaced by other optical elements.</p> |
