Patent ID: 7576870

Claim:
A measurement apparatus which measures a wavefront aberration of an optical system to be measured, the apparatus comprising: a detection unit configured to detect an interference pattern formed by light having passed through a mask inserted on an object plane of the optical system to be measured, and a mask inserted on an image plane of the optical system to be measured, wherein a plurality of first pinholes each of which has a first diameter and which are spaced apart from each other by a distance at which said plurality of first pinholes do not have coherence, and a plurality of second pinholes each of which has a second diameter larger than the first diameter and is spaced apart from a corresponding one of said plurality of first pinholes by a distance at which said each first pinhole and said corresponding second pinhole have coherence are formed in the mask inserted on the object plane of the optical system to be measured, and a plurality of third pinholes each of which has a third diameter and which are formed to receive light beams having passed through said plurality of first pinholes and the optical system to be measured, and a plurality of fourth pinholes each of which has a fourth diameter smaller than the third diameter and which are formed to receive light beams having passed through said plurality of second pinholes and the optical system to be measured are formed in the mask inserted on the image plane of the optical system to be measured.