| 摘要 |
<p>A diffractive optical element having a design wavelength lambda , includes a diffractive surface for diffracting predetermined light corresponding to the design wavelength, and a mark shaped so that, with regard to the predetermined light, a phase difference corresponding to a multiple, by an integer, of the design wavelength lambda is produced between (i) a light ray, of the predetermined light, as transmitted through or reflected by the mark and (ii) a light ray, of the predetermined light, as transmitted through or reflected by a portion adjacent to the mark, and that, with regard to second light of a second wavelength lambda ' different from the design wavelength lambda , no phase difference corresponding to a multiple, by an integer, of the second wavelength lambda ' is produced between (a) a light ray, of the second light, as transmitted through or reflected by the mark and (b) a light ray, of the second light, as transmitted through or reflected by a portion adjacent to the mark. <IMAGE> <IMAGE></p> |
