| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavefront sensor capable of measuring a wavefront from a light source which cannot be recognized as a single point, such as, a surface light source or a plurality of point light sources. SOLUTION: A wavefront of light to be measured incident to an entrance pupil P is split by a semi-transparent mirror 3 into a first optical path L1 and a second optical path L2. A wavefront W1 propagating in the first optical path L1 transmits through a first optical path difference compensation member 7; and a wavefront W2 propagating in the second optical path L2 transmits through a second optical path difference compensation member 8. The wavefronts W1 and W2 are again mixed by a semi-transparent mirror 6, while being shifted in position by a sharing amount S from each other; and form the interference fringes on a side face M of an interferometer. the intensity distribution of the interference fringes is measured by a photodetector 9, and the shape of the wavefront of the light to be measured is measured by a wavefront measurement section 10. The difference in the optical paths that occurs between wavefronts W1' and W2' extending to the side face M, while being tilted due to the incoming direction of the wavefront is compensated beforehand, when the wavefronts W1' and W2' are transmitted through the first and second optical path difference compensation members 7 and 8, respectively. COPYRIGHT: (C)2009,JPO&INPIT
|
