| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technology that is advantageous for highly accurately measuring a distance corresponding to a difference in an optical path length between reference light and test light.SOLUTION: The measuring instrument has: a first optical system through which first test light obtained by dividing light emitted from a light source 101 passes, and a second optical system through which second test light passes; a detection unit 113 that detects interference light between each of the first test light and the second test light reflected by a test surface 100 and reference light reflected by a reference surface 104; and a processing unit 115 that calculates a distance on the basis of the interference light detected by the detection unit 113. Optical power in the first optical system and optical power in the second optical system are different from each other, and a distance between condensing points P01 and P02 of the first test light on the test surface side and the test surface, and a distance between condensing points P11 and P12 of the second test light on the test surface side and the test surface are different from each other according to each of a plurality of wavelengths. The measuring instrument further has a light guide unit that guides the first test light having a wavelength corresponding to the condensing point at a predetermined distance between the condensing point and the test surface and the second test light having a wavelength corresponding to the condensing point at a predetermined distance between the condensing point and the test surface to the detection unit 113.</p> |
