| 摘要 |
PROBLEM TO BE SOLVED: To measure positional relation between a condensing point and a detector of an illumination optical system relatively simply and highly precisely.SOLUTION: A measuring apparatus for measuring optical performance of a test optical element comprises: an illumination optical system L for emitting spherical wave light; and a calculating part 12 for moving at least one of a diffraction grating 7 and a detector 9 in an optical axis direction, causing the detector 9 to image a plurality of interference fringes before and after move, and calculating a condensing point S of the illumination optical system on the basis of a movement amount and a spatial frequency of the plurality of interference fringes. |
