| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical interferometer capable of obtaining a change in the thickness of a workpiece. <P>SOLUTION: The optical interferometer 100 comprises: a first optical interferometer 200 arranged at the front side of the workpiece W; and a second optical interferometer 300 arranged at the rear side of the workpiece W. The first optical interferometer 200 and the second optical interferometer 300 comprise: light discharge sections 210, 310; wire grids 220, 320; and interference fringe acquisition sections 230, 330. The wire arrangement direction of the wire grid 220 in the first optical interferometer 200 is orthogonal to that of the wire grid 320 in the second optical interferometer 300. While no workpieces W are arranged, the wire grid 220 in the first optical interferometer 200 reflects light from the second optical interferometer 300 to generate object light, and the wire grid 320 in the second optical interferometer 300 reflects light from the first optical interferometer 200 to generate object light. <P>COPYRIGHT: (C)2008,JPO&INPIT |
