Projection exposure objective e.g., for lithography systems, has central obscuration and forms intermediate images between mirrors

摘要

A projection objective for imaging an object, has a mirror unit (TS2,TS3;K) which is designed so that within the mirror unit, especially between two opposite facing mirrors (S1,S2), at least one intermediate image (ZB2) is generated. The mirror unit comprises two concave mirrors with their concave surfaces pointing towards one another.