Abstract: An optical apparatus for a lithography system comprises at least one optical element comprising an optical surface. The optical apparatus also comprises one or more actuators for deforming the optical surface. A strain gauge device is provided for determining the deformation of the optical surface. The strain gauge device comprises at least one optical fiber that maintains polarization.

Abstract: A switch bay for a high-voltage switchgear assembly includes three gas-insulated circuit breakers each for corresponding one of first, second and third current phases. The circuit breakers are arranged parallel to one another along an x direction. Three switch disconnectors are provided for a corresponding one of the first, second and third current phases. The switch disconnectors each have a corresponding isolating gap. The isolating gaps are arranged parallel to one another. A first busbar phase conductor section of the first current phase and a second busbar phase conductor section of the second current phase extend parallel to one another along a y direction, which runs transversely with respect to the x direction. A busbar connection is provided for connection of a third busbar phase conductor section of the third current phase.