摘要 |
An interferometric measuring device for measuring shapes of rough surfaces of an object to be measured. The measuring device has a radiation generator that emits a short-coherent radiation; a beam splitter for forming a reference beam that is directed toward a device having a reflecting element for periodically changing the light path, and a measuring beam which is directed toward the object to be measured; a superposition element at which the measuring beam coming from the object to be measured and the reference beam coming from the device are made to interfere; and a photodetector that receives the interfered radiation. In a simple design, a high measuring accuracy is achieved in that the device for changing the light path has a parallelly-displacing arrangement arranged in the beam path, and, fixedly arranged behind it, the reflecting element, and that a compensating grating is arranged in the beam path of the reference beam upstream of the parallelly-displacing arrangement. The reference beam is diffracted at the grating both prior and subsequent to passing through the parallelly-displacing arrangement.
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