Optical element for forming object images and/or focusing electromagnetic radiation has at least one region of at least part of zone plate with filter function giving different transmissivity

摘要

The optical element has at least one part of a Fresnel zone plate (20,22) with annular zones (24) or sections of annular zones that are opaque for the radiation (11) and zones (23) or sections transparent for the radiation. At least one region of at least one part of the zone plate has a filter function with which the transmissivity for the radiation is different. Independent claims are also included for the following: a measurement system, especially for measuring inner regions of 3D specimens with high positional resolution and equipment for altering properties of a region of a specimen.