Abstract: A modulator unit for modulating the phase of a polarization component of an optical signal contains a polarizing beam splitter and a phase shifter. The beam splitter splits an input signal into a first and a second polarization components having different polarization directions and sends the components in opposite directions via an optical ring containing the phase shifter. A polarization rotator is arranged in the optical ring, which changes the polarization direction of passing optical signals, so that the polarization components arriving at the phase shifter are polarized in the same direction. The phase shifter changes the polarization directions of the incoming optical signals such that they are polarized orthogonally to one another in the phase shifter. One polarization component is modulated. When the optical signals leave the phase shifter, their polarization direction is brought back to the original polarization direction.

Abstract: The method enables optical measurements of an oscillatory, and particularly structured, membrane in an environment which is subjected to gas flows and/or acoustic excitations. A device for measuring the membrane is focused on the same. An optically transparent film is provided, and the film and the membrane are arranged in such a manner that the gas flows and/or the acoustic excitations reach the membrane only by passing through the film. The film enables a diminishing of the external air movements and thus oscillations of the membrane so that the membrane can be precisely measured.

Abstract: The method enables optical measurements of an oscillatory, and particularly structured, membrane in an environment which is subjected to gas flows and/or acoustic excitations. A device for measuring the membrane is focused on the same. An optically transparent film is provided, and the film and the membrane are arranged in such a manner that the gas flows and/or the acoustic excitations reach the membrane only by passing through the film. The film enables a diminishing of the external air movements and thus oscillations of the membrane so that the membrane can be precisely measured.

Abstract: A method and a device for analyzing structures of a photomask are described. In a first method step, at least one trench is created in the photomask, so that at least one lateral limitation of the trench forms a section through the structures to be analyzed. Then, the structures to be analyzed are scanned by scanning beams, which are guided through the trench on its lateral limitation.