| 摘要 |
PROBLEM TO BE SOLVED: To measure with high accuracy the shape of a test surface that is rotationally symmetric and has a complicated shape by optical interferometry. SOLUTION: The relative position of the test surface 80 is sequentially changed from a reference position where a surface axis C is aligned with a measurement optical axis L so that the measurement optical axis L is sequentially moved to a plurality of annular regions obtained by dividing the test surface 80 in a radial direction. The test surface 80 is rotated around a rotation axis E whenever the relative position is changed. Measurement light that travels while being converged by a Mirau objective interference optical system 23 is applied to the rotating test surface 80, and a one-dimensional image sensor 32 captures interference fringes at each of a plurality of rotational positions. The shape information of each annular region is determined on the basis of the captured interference fringes at each rotational position, and pieces of the shape information are connected to determine the shape information of the entire measurement region. COPYRIGHT: (C)2010,JPO&INPIT
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