Abstract: A facet mirror assembly has a carrier body for a plurality of individual mirrors. Reflection surfaces of the individual mirrors are individually tiltable, via assigned tilt actuators, about at least one tilt axis within an individual mirror tilt angle range around a neutral tilt position between a maximum angle and a minimum angle. The individual mirrors have at least two different neutral tilt positions in a range around a mean value of a total tilt angle range. The result can be a facet mirror assembly having improved properties with respect to a tilt actuator system of the facet mirror assembly.

Abstract: An optical device, such as for a lithography system, comprises: at least one optical element having at least one optical surface; one or more actuators to tilt the optical surface of the optical element; and a measuring device to detect a tilt of the optical surface from an idle position. The measuring device has at least one waveguide which forms a closed measuring section. The waveguide is designed for coupling in and propagating one or more modes of a measuring beam. The waveguide is arranged such that a tilt of the optical surface influences the measuring beam propagating through the waveguide. The measuring device is designed to detect an influencing of the measuring beam caused by the tilt of the optical surface.

Abstract: A rotation-rate sensor having a substrate with main extension plane, for detecting a rotation rate, extending in a direction parallel/orthogonal to the main plane; the sensor including a primary/secondary pair of seismic masses; the primary pair having first/second primary masses; the secondary pair having first/second secondary masses; the first/second primary masses being movable relative to the substrate along a primary deflection direction extending parallel to the main plane; the first/second secondary masses being movable relative to the substrate along a secondary deflection direction extending parallel to the main plane; the first/second primary masses and the first/second primary masses being movable antiparallel or parallel to one another corresponding to the deflection direction, essentially extending orthogonally to the secondary deflection direction; and the primary pair and/or secondary pair being drivable so that, based on sensor rotation, the Coriolis force leads to deflection of the first/sec