ABERRATION MEASUREMENT APPARATUS AND ABERRATION MEASUREMENT METHOD

摘要

An aberration measurement apparatus and an aberration measurement method are provided to evaluate the capacity of a cooling unit by measuring the change of aberration according to time while an image optical system is cooled by using the cooling unit. A measurement light is used to measure aberration of an image optical system. An illumination system(10) supplies a background light different from the measurement light to the image optical system. A separation member(3) separates the measurement light from the background light passing through the image optical system. A measuring unit(4) measures the aberration of the image optical system on the basis of the measurement light separated by the separation member. The illumination system supplies the measurement light and the background light specially separated on an object surface of the image optical system. The illumination system includes an illumination main frame(1) and a pattern light generating member. The illumination main frame supplies a light to the object surface of the image optical system. A cooling unit(5) cools the image optical system using circulation water.