Optical system

摘要

An optical element (1) of an optical system has at least one chamber (5) that is sealed against atmospheric pressure and is enclosed by boundary surfaces and that has a fluid filling. At least one of the boundary surfaces of the chamber (5) is exposed at least partially to illumination light. It is configured so that a change in the fluid pressure inside the chamber (5) results in a change in non-rotational-symmetric imaging properties of the optical element (1) having n-fold symmetry. For this purpose, a fluid source has a fluid connection to the chamber via a fluid supply line (17). Furthermore, a control device is provided for the pressure in the fluid filling.