| 摘要 |
<p>An optical integrator of the present invention has a plurality of wavefront dividing elements two-dimensionally arrayed, and is so configured that a ray group obliquely incident to an optical-axis center of an entrance face of each wavefront dividing element is emitted in parallel with the optical axis from the wavefront dividing element. In each of a required number of wavefront dividing elements (100A) out of the plurality of wavefront dividing elements, at least one curved optical face (100a, 100b) of the wavefront dividing element (100A) is formed as inclined around an axis (104) along a predetermined direction (x-direction) passing an optical-axis center (100aa) of an entrance face (100a) of the wavefront dividing element (100A) and being perpendicular to the optical axis AXe.</p> |
