PINHOLE UNIT, POINT DIFFRACTION INTERFEROMETER, AND METHOD OF MANUFACTURING PROJECTION OPTICAL SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce the intensity unevenness of the spherical waves formed by a pinhole used for a point diffraction interferometer or the like. SOLUTION: The pinhole unit is provided with a pinhole plate 12 which has the pinhole 12B of a diameter smaller than the diffraction limit of a prescribed convergent luminous fluxe and induces the spherical waves on the exit side of the pinhole 12B according to the convergent luminous fluxes made incident on the pinhole 12B and a reflection plate which is disposed on the incident side of the pinhole plate 12 so as not to hinder the optical path of the convergent luminous fluxes and guides at least part of the extra rays vignetted by the edge of the pinhole 12B among the convergent luminous fluxes. The intensity unevenness of the spherical waves can be reduced if the shape of the reflection surface 11a of the reflection plate 11 is optimized. COPYRIGHT: (C)2004,JPO