| 摘要 |
<p>An optical heterodyne interference apparatus has light producing means producing a first light and a second light differing in frequency from each other, a beam splitter for directing the first light to an object to be measured and directing the second light to a reference surface, and combining the first light and the second light passed through the object to be measured and the reference surface, respectively, detecting means for obtaining a beat signal on the basis of the combined lights, and optical means provided in the optical path from the light producing means so as to extinguish one of the first light and the second light and direct the other light to the object to be measured and the reference surface. <IMAGE></p> |
