Patent attributes
The invention provides a measurement apparatus which measures a wavefront aberration of an optical system to be measured, the apparatus includes a measurement mask which is inserted on an object plane of the optical system to be measured, and includes a plurality of reflection units configured to generate spherical waves by reflecting light, the measurement mask including a reflection layer configured to reflect the light, a first layer which is stacked on the reflection layer, has a plurality of openings, and is made of a first substance, and a second layer which is stacked on the first layer, has a window configured to expose a region in which the plurality of openings are arrayed, and is made of a second substance different from the first substance, wherein the plurality of reflection units are formed by portions of the reflection layer, which are exposed through the plurality of openings.
