Abstract: Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device.

Abstract: A pressure sensor is disclosed with at least one pressure sensing element, the pressure induced changes in the optical properties of which are evaluated by illumination with at least one light source. The pressure sensor can include at least two semiconductor-based pressure sensing elements located in individual pressure chambers, which sensing elements are located essentially adjacent to each other. The sensing elements can be irradiated with the same light source, wherein the light transmitted through the sensing elements is detected using at least two corresponding detectors, and wherein the differential pressure in the two pressure chambers is evaluated based on the output of these detectors.

Abstract: An exemplary gas-insulated switchgear device is disclosed which includes a current sensor and a voltage sensor located at a partition insulator. The current sensor can include a magneto-optical fiber on a flexible carrier strip and can be manufactured separately for being easily mounted to an assembled switchgear device. The current sensor can include an electro-optical fiber extending radially into the partition insulator and whose ends are embedded in recesses in the bus bar as well as in the metal embracing of the partition insulator for accurately integrating the voltage.

Abstract: An electro-optical high-voltage sensor includes a waveguiding sensing fiber of an electro-optical material. The electrical field of the voltage to be measured is substantially parallel to the longitudinal axis of the sensing fiber. The sensing fiber carries two orthogonally polarized light waves, with the applied field affecting the birefringence between the waves. Using an electro-optical waveguiding fiber in this configuration allows the voltage between two widely spaced points to be accurately measured.

Abstract: An exemplary gas-insulated switchgear device is disclosed which includes a current sensor and a voltage sensor located at a partition insulator. The current sensor can include a magneto-optical fiber on a flexible carrier strip and can be manufactured separately for being easily mounted to an assembled switchgear device. The current sensor can include an electro-optical fiber extending radially into the partition insulator and whose ends are embedded in recesses in the bus bar as well as in the metal embracing of the partition insulator for accurately integrating the voltage.

Abstract: A pressure sensor is disclosed wherein pressure induced changes in birefringent properties of an optical sensing element are read out by transmission of at least one light beam. The pressure sensor can include at least one single-material transparent body which is subjected to at least two different pressures (p1, p2) in at least two different regions via at least two pressure chambers. The transparent body can transmit by a parallel or minimally divergent light beam without total reflection in the body such that the pressure-induced birefringence and a corresponding differential phase shift between linear polarisation components of the light beam depends on a difference of the different pressures (p1, p2).

Abstract: Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device.

Abstract: To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero.

Abstract: A pressure sensor is disclosed wherein pressure induced changes in birefringent properties of an optical sensing element are read out by transmission of at least one light beam. The pressure sensor can include at least one single-material transparent body which is subjected to at least two different pressures (p1, p2) in at least two different regions via at least two pressure chambers. The transparent body can transmit by a parallel or minimally divergent light beam without total reflection in the body such that the pressure-induced birefringence and a corresponding differential phase shift between linear polarisation components of the light beam depends on a difference of the different pressures (p1, p2).

Abstract: A pressure sensor is disclosed with at least one pressure sensing element, the pressure induced changes in the optical properties of which are evaluated by illumination with at least one light source. The pressure sensor can include at least two semiconductor-based pressure sensing elements located in individual pressure chambers, which sensing elements are located essentially adjacent to each other. The sensing elements can be irradiated with the same light source, wherein the light transmitted through the sensing elements is detected using at least two corresponding detectors, and wherein the differential pressure in the two pressure chambers is evaluated based on the output of these detectors.

Abstract: A simple, multi-spectral flame detector is disclosed. Such a flame detector has an optical imaging system that is adapted to project several images of the flame onto the same camera. The images are from differing spectral regions. The imaging system comprises several lens devices arranged side by side, e.g., the imaging optics comprise several lens devices arranged side by side, such that each lens device is receiving part of the light from the flame. Each lens device projects one image onto one region of the camera. In this configuration, no beam splitters or mirrors are required, such components being expensive and difficult to align.

Abstract: To measure a sum of electrical currents in different conductors, light is led in an optical sensing fiber around all the conductors. The sensing fiber can be wound around the conductors in a single loop or in several individual loops. Interspersed polarization maintaining fibers and retarders can be used to transfer the light between individual loops for preventing undesired signals from stray magnetic fields. The method has high accuracy is particularly suited for measuring large currents that sum up to zero.

Abstract: A fiber-optic sensor head is disclosed for an optical current or magnetic-field sensor which can have an optical fiber which includes a magnetooptically active sensor fiber which is optically connected to at least one polarization-defining element. The sensor fiber can be arranged in a magnetic field to be measured or around a conductor carrying current to be measured and can be in the form of a coil, with the coil defining a coil plane (A) with a surface normal (Ns), and with the at least one polarization-defining element having a marked axis (f). The sensor head can be flexible in the area of the sensor fiber, and an adjustment means can be provided for adjustment of a predeterminable angle ? between the marked axis,(f) and the surface normal (Ns) or for adjustment of predeterminable angles ?, ?? between the marked axes (f) and the surface normal (Ns).

Abstract: A high-voltage component, having a first end and a second end, whereby the first end is on a high-voltage potential with respect to the second end. An insulating part, is arranged between the first end and the second end, and an optical fiber is integrated in the high-voltage component and extends from the first end to the second end. A capillary extends from the first end to the second end and is arranged within the insulating part. The inside diameter of the capillary exceeds the outside diameter of the fiber, and the fiber is arranged within the capillary. The capillary includes a protective medium to achieve a dielectric strength in the capillary, which dielectric strength is suitable for the operating conditions.

Abstract: The fiber-optic sensor head (2) for a current or magnetic field sensor comprises an optical fiber which contains a magnetooptically active sensor fiber (3) and at least one polarization-maintaining supply fiber (5), which are optically connected, with the sensor fiber (3) having its fiber protective sheath removed. The sensor head (2) furthermore contains a capillary (6), in which at least the sensor fiber (3) is arranged. Furthermore, the sensor head (2) can be bent in the area of the sensor fiber (3), and a friction reducing means (7) is provided in the capillary (6), in order to reduce the friction between the sensor fiber (3) and the capillary (6). The friction reducing means (7) is advantageously an oil or a dry lubricating means (7). The capillary (6) is advantageously encased by a capillary casing (8). The sensor (2) allows very largely temperature-dependent measurements, is easy to install and allows measurements on large cross-section conductors.

Abstract: A high-resolution fiber laser sensor for measuring a quantity to be measured M has a pumping light source, a fiber laser and a detection/evaluating unit. The fiber laser has: a birefringent first end reflector, a second end reflector, a laser-amplifying fiber, a sensor fiber and a mode coupling. The laser-amplifying fiber, the sensor fiber and the mode coupling are arranged between the end reflectors. In the fiber laser, light is capable of propagating in two optical states which are orthogonal to one another due to their polarization and/or their transversal space structure. The orthogonal optical states can be coupled to one another by the mode coupling. In the fiber laser, a number of longitudinal modes are capable of oscillating in each of the two optical states. In the sensor fiber a change in the birefringence for the two orthogonal optical states can be achieved by interaction of the quantity to be measured with the sensor fiber.

Abstract: The electra-optical voltage sensor has an electra-optically active medium and a distance medium between two electrodes, between which the voltage V to be measured is present. The media and the thicknesses d1, d2 of the media are chosen in such a way that the measured voltage signal has no temperature dependence. By way of example, the thicknesses d1, d2 are chosen in such a way that the influence of the temperature dependences of critical electra-optical coefficients and dielectric constants of the media on the voltage signal cancel one another out. The two media are advantageously arranged in the form of a rod, comprising an alternating arrangement of cylindrical elements of the two media, between the electrodes. BGO and fused silica may advantageously be used as media. The sensor is preferably cast in silicone.

Abstract: The voltage sensor for measurement of a voltage V, which is present between two electrodes (3, 4) and generates an electric field E, comprises at least two layers (1a, 2a) made of electro-optically active material and being arranged along a light path (5). Through the layers there passes a light beam, the phase and/or state of polarization of which is influenced on account of the electro-optical effect. The orientation of the electro-optically active layers (1a, 2a) relative to the light path and the electric field E is chosen in such a way, that the influencing of the light (5) in the second layer (2a) counteracts the influencing of the light (5) in the first layer (1a). In this way, it is possible to realize a sensor with a high half wave voltage, so that high voltages V can be measured unambiguously. A plurality of first and second electro-optically active layers are advantageously arranged between the electrodes (3, 4).

Abstract: The subject matter of the present invention is a fiber Bragg grating sensor 1, 25 which is suitable, in particular, for measuring differential pressures and flow rates v1 in oil drill holes. The sensor principle according to the invention is based on using a transducer 1 with two pressure chambers 7a, 7b to convert a hydrostatic pressure difference between two liquid or gaseous media 11a, 11b into a longitudinal fiber elongation or fiber compression and measuring it via the displacement of the Bragg wavelength &Dgr;&lgr;B of at least one fiber Bragg grating 3, 4. Exemplary embodiments are specified which have two fiber Bragg gratings 3, 4 which are sensitive to elongation in opposite senses and which have temperature-compensating transducers 1, and which have a plurality of transducers 1 in a wavelength-division-multiplexing configuration. One embodiment relates to measuring a flow rate v1 with the aid of a venturi tube 23.

Abstract: A method is described for producing a fiberoptic waveguide with a basic segment (11) and a phase shift segment (12), the basic segment (11) and phase shift segment (12) having fiber cores (K) of the same form and the fiber cores being aligned at a defined angle (&agr;) to one another. In the method, use is made of an optical fiber (1) having a fiber core (K) of the abovenamed form, which fiber is twisted at least approximately by the abovenamed defined angle (&agr;) and held fixed in this torsional position. Subsequently, a stress-relief zone (13) is heated inside the twisted fiber (1) until the torsion is released inside the stress-relief zone (13) and the basic segment (11) is produced on one side of the stress-relief zone (13) and the phase shift segment (12) is produced on the other side. In this case, the fixing of the torsional position is maintained until after solidification of the stress-relief zone (13).