Abstract: Provided is a surgical operating system, comprising a surgical tool, an optical sensor arranged on or in the surgical tool and configured to measure a distance (8-x) of the surgical tool from a tissue for a plurality of directions (6-x) and/or for a plurality of mutually separated punctiform spatial regions (7-x), an optical coherence tomography measuring device connected to the optical sensor and configured to determine the respective distance (8-x) from the tissue for the plurality of directions (6-x) and/or punctiform spatial regions (7-x) by means of the sensor and to provide the determined distances (8-x). Also provided are a surgical tool and a method for safeguarding a surgical operation.

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: Apparatuses and test cards for testing photonic integrated circuits, corresponding systems and methods, and photonic integrated circuits are provided. A test card can be imaged via an optical unit onto a photonic integrated circuit to be tested. Parallel illumination of the photonic integrated circuit at different locations is possible in this way.

Abstract: In a longitudinally installed four wheel drive train of a motor which includes a front drive shaft, which transmits the engine driving torque to the front axle from the rear end of the vehicle transmission the front drive shaft comprises at least at its rear end two opposite radially projecting pins extending into longitudinal grooves formed in a gear wheel of a front drive structure so as to be axially movably and pivotally supported therein.