摘要 |
A zone plate includes a plurality of consecutively arranged, adjacent, and alternating first and second regions. The first regions are arranged to be substantially transparent to a first predetermined wavelength of radiation and a second predetermined wavelength of radiation that is different from the first predetermined wavelength of radiation. The second regions are arranged to be substantially opaque, diffractive, or reflective to the first predetermined wavelength of radiation and substantially transparent to the second predetermined wavelength of radiation. |