Abstract: The current in a conductor is measured by exploiting the Faraday effect in a sensing fiber. The light returning from the sensing fiber is split into at least two parts, at least one of which is analyzed by a first circular analyzer for generating a first signal. A second part may e.g. be analyzed by a second circular analyzer, and a third part may be analyzed by a linear analyzer. By combining the signals obtained in this way, the current induced phase delay in the returning light can be measured efficiently and accurately.

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: 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: An optical current sensor having a reflection interferometer (1, 10) has, in its fiber-optic lead (2), a polarization-maintaining first fiber branch (20) for two forward-traveling orthogonally polarized waves and a polarization-maintaining second fiber branch (20?) for two backward-traveling orthogonally polarized waves. In this case, the two fiber branches (20, 20?) are connected to one another via a coupler (8) on the sensor side. The first fiber branch (20) is connected to a light source (4) and the second fiber branch (20?) is connected to the detector (5). A means for phase shifting (7) is funcionally connected to at least one of the fiber branches (20, 20?). It is thus possible to achieve a quasi-static control of the phase shift of the waves, so that less stringent requirements can be made of the means for phase shifting than of the phase modulators that are usually used in current sensors of this type.

Abstract: The invention relates to a fiberoptic current or magnetic field sensor having a plurality of sensor heads, and to a corresponding measurement method. The sensor has a light source: N?2 sensor heads; at least one phase modulation unit; a detector; a control and evaluation unit. The at least one phase modulation unit is connected to at least one of the sensor heads. Lightwaves can be differentially phase-modulated in a non-reciprocal fashion by means of the at least one phase modulation unit. Modulation amplitudes ?0,n and modulation frequencies vn are selected as a function of modulation-relevant optical path lengths ln.

Abstract: A high-resolution fiber laser sensor for measuring a quantity to be measured M has a pumping light source (2), a fiber laser (1) and a detection/evaluating unit (3). The fiber laser (1) has: a birefringent first end reflector (11), a second end reflector (12), a laser-amplifying fiber (13), a sensor fiber (14) and a means for mode coupling (15). The laser-amplifying fiber (13), the sensor fiber (14) and the means for mode coupling (15) are arranged between the end reflectors (11, 12). In the fiber laser (1), light is capable of propagating in two optical states (x, y; LP?01, LP?11) which are orthogonal to one another due to their polarization and/or their transversal space structure. The orthogonal optical states (x, y; LP?01, LP?11) can be coupled to one another by the means for mode coupling (15). In the fiber laser (1), a number of longitudinal modes (LMxp, LMxp+1 . . . , LMyq, LMyq+1 . . . ; LM01p, LM01p+1 . . . , LM11q, LM11q+1 . . .

Abstract: For measuring an electric voltage in an electro-optic voltage converter, polarized light of two wavelengths is sent through a medium. At the output side, the light is led through a polarizer and the remaining signal is measured. For compensating a temperature dependence of the electro-optic coefficients, the measured results at both wavelengths are compared, and the voltage value consistant with both measurements is used.

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: 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 invention relates to a DFB fiber laser sensor (1). A measurement quantity makes it possible to induce a linear birefringence between mode pairs of the laser-amplifying fiber (2) and to measure an associated beat frequency (??1, ??2, ??3). According to the invention, the laser-amplifying fiber (2) has a nonrotationally symmetrical structure, so that it is possible to detect isotropic pressures p, acoustic waves or chemical substances that can be added radially to the laser-amplifying fiber (2). In a second aspect of the invention, an emission wavelength range and parameters (a, b, ?N) of the laser-amplifying fiber (2) and also a grating period L of the fiber Bragg grating resonator (3) are coordinated with one another such that at least two different spatial modes (LP01, LP11even, LP11odd, LP21even) are propagatable and it is possible to measure beat frequencies (??1, ??2, ??3) between oscillatory longitudinal laser modes assigned to them.

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: An optical current or magnetic field sensor has a sensor head which has a first phase delay element (13), a second phase delay element and a sensor fiber (15) The two phase delay elements (13) are optically connected to opposite ends of the sensor element (15), and the phase delay angle &rgr; on at least one of the phase delay elements (13) deviates by an angle &egr;, with &egr;≠0°, from 90°. Linearly polarized light waves (3) are injected into the first phase delay element (13), with a polarization axis (y′) of these linearly polarized light waves (3) including an angle which deviates from 45° by an angle &Dgr;&agr;, with &Dgr;&agr;≠0°, with a principal axis (y) of the first phase delay element (13). The angle &Dgr;&agr; is selected as a function of at least the angle &egr;.

Abstract: The electro-optical voltage sensor has an electro-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 electro-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 invention relates to a fiberoptic current or magnetic field sensor having a plurality of sensor heads (H), and to a corresponding measurement method. The sensor has: a light source (1); N≧2 sensor heads (H); at least one phase modulation unit (PME) having at least one phase modulator (PM); a detector (2); a control and evaluation unit (5). The at least one phase modulation unit (PME) is optically connected to at least one of the sensor heads (H). Linearly polarized lightwaves can be differentially phase-modulated in a non-reciprocal fashion by means of the at least one phase modulation unit (PME).

Abstract: An optical current sensor having a reflection interferometer (1, 10) has, in its fiber-optic lead (2), a polarization-maintaining first fiber branch (20) for two forward-traveling orthogonally polarized waves and a polarization-maintaining second fiber branch (20′) for two backward-traveling orthogonally polarized waves. In this case, the two fiber branches (20, 20′) are connected to one another via a coupler (8) on the sensor side. The first fiber branch (20) is connected to a light source (4) and the second fiber branch (20′) is connected to the detector (5). A means for phase shifting (7) is funcionally connected to at least one of the fiber branches (20, 20′). It is thus possible to achieve a quasi-static control of the phase shift of the waves, so that less stringent requirements can be made of the means for phase shifting than of the phase modulators that are usually used in current sensors of this type.