| 摘要 |
PURPOSE: To easily and rapidly adjust a lens tilt correction in the measurement of the lens with an interferometer. CONSTITUTION: The lens is formed to such a shape that an area outside the effective diameter 12 of a 1st plane 1 may return reflected light F1 which is parallel to an optical axis A with reference to incident light L which is parallel to the optical axis A, and also, the lens is formed to such a shape that the light F2 reflected by a 2nd plane 2 may not cause the interference with the light F1 reflected by the 1st plane, because the flat part 23 in the area outside the effective diameter 22 of the 2nd plane 2 is constituted of such a plane that is not perpendicular to the optical axis A. |
