| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device useful as an improved spectrum impurity filter. <P>SOLUTION: A zone plate includes a plurality of first and second regions which are adjacently and alternately arranged continuously. The first region is structured to be substantially transmissive on a first predetermined radiation wavelength and a second predetermined radiation wavelength different from the first predetermined radiation wavelength. The second region is structured to be substantially non-transmissive, diffractive, or reflective on the first predetermined radiation wavelength, and is substantially transmissive on the second predetermined radiation wavelength. <P>COPYRIGHT: (C)2010,JPO&INPIT |
