OBLIQUE INCIDENCE INTERFEROMETER DEVICE

摘要

PURPOSE:To measure an object surface by forming the 2nd diffraction grating by holography and measuring the sample by using the 2nd formed diffraction grating. CONSTITUTION:Laser light emitted by a laser oscillator 1 is diverged by a diverging lens 2. Then the laser light after passing through a pinhole 10 and being reflected by a reflecting mirror 11 is collimated by a collimator lens 3 into parallel luminous flux. The 1st diffraction grating 4 diffracts this parallel laser light. A mount table 5 is movable in three dimensions. The 2nd diffraction grating 6 consists of a holographic grating and the flatness of the sample is inspected accurately by properties characteristic to the holography that the holographic grating itself has even if the collimator lens 3 and the 1st diffraction grating 4 are manufactured with slightly low precision. Consequently, the flatness of the sample is measured accurately.