| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a length measuring interferometer that make high-precision refractive index correction even when an air composition has a spatial distribution. <P>SOLUTION: A light wave interference measurement device calculates a geometric distance of an optical path length difference between a reference surface 52 and a test surface 53 by measuring the optical path length difference using a multiwavelength light source 10 for interference measurement. The light wave interference measurement device comprises: a light source 20 for partial pressure measurement; a dispersion interferometer 30 which measures dispersion of air at a wavelength of the multiwavelength light source; a first partial pressure detector 40 which measures partial pressure of component gas of air of the dispersion interferometer; a length measuring interferometer 50 which measures the optical path wavelength difference between the reference surface and test surface at the wavelength of the multiwavelength light source; a second partial pressure detector 60 which measures partial pressure of component gas of air of the length measuring interferometer; and an analyzer 70 which calculates the geometric distance of the optical path length difference between the reference surface and test surface by calculating an air dispersion ratio other than the component gas of the dispersion interferometer from a detection result of the first partial pressure detector, and also calculating dispersion of the air of the length measuring interferometer from the air dispersion ratio other than the component gas and a detection result of the second partial pressure detector. <P>COPYRIGHT: (C)2012,JPO&INPIT |
