A fiber optic sensor and related method are described, with the sensor including a cross-coupling element in the optical path between a polarizing element and a sensing element, but separated from the sensing element itself; with the cross-coupling element generating a defined cross-coupling between the two orthogonal polarization states of the fundamental mode of a polarization maintaining fiber guiding light from the light source to the sensing element thus introducing a wavelength-dependent or temperature-dependent sensor signal shift to balance wavelength-dependent or temperature-dependent signal shifts due to other elements of the sensor, particularly signal shifts due to the wavelength dependence of the Faraday effect or the electro-optic effect constant.

A system detects and/or predicts metal ion plating events of a metal ion energy storage device. The system includes an optical sensor disposed internally within or externally on a metal ion energy storage device wherein the optical sensor has an optical output that changes in response to strain within a metal ion energy storage device. A current sensor senses current through the metal ion energy storage device. Plating detection circuitry measures a wavelength shift in the optical output of the optical sensor and estimates a state of charge (SOC) of the metal ion energy storage device based on the current. An expected wavelength shift is determined from the estimated SOC. A plating event can be detected and/or predicted based on the difference between the expected wavelength shift and the measured wavelength shift.

One aspect of the present technology relates to an optical electric field sensor device. The device includes a non-conductive housing configured to be located proximate to an electric field. A voltage sensor assembly is positioned within the housing and includes a crystal material positioned to receive an input light beam from a first light source through a first optical fiber. The crystal material is configured to exhibit a Pockels effect when an electric field is applied when the housing is located proximate to the electric field to provide an output light beam to a detector through a second optical fiber. An optical cable is coupled to the housing and configured to house at least a portion of the first optical fiber and the second optical fiber. The first light source and the detector are located remotely from the housing. A method of detecting an electric field is also disclosed.

A measuring device measures an electrical current and contains a light source for generating a polarized primary light signal for feeding into a Faraday sensor unit, and a detector for detecting a secondary light signal provided by the Faraday sensor unit and polarization-altered in relation to the primary light signal. An optical-electrical compensation element, by which the polarization alteration of the secondary light signal can be compensated via an opposite polarization alteration, and a measurement signal, according to the opposite polarization alteration, for the electrical current can be deduced. A method for measuring an electrical current by use of the measuring device is further disclosed.

A method for distinguishing an arc from a luminous gas at least containing metal vapor includes sensing light in a monitoring region and determining a first intensity I.sub.1 of the sensed light at a first wavelength 1 and a second intensity I.sub.2 of the sensed light at a second, greater wavelength 2. The ratio I.sub.1/I.sub.2 between the first intensity I.sub.1 and the second intensity I.sub.2 is determined. The sensed light is associated with an arc if said ratio I.sub.1/I.sub.2 is greater than a specifiable first threshold value and/or with a luminous gas at least containing metal vapor if said ratio I.sub.1/I.sub.2 is less than a specifiable second threshold value.

Within electrical test equipment systems comparator bridges are employed to provide the required dynamic range, accuracy, and flexibility. However, whilst bridge based measurement configurations remove many of the issues associated with making measurements at accuracies of sub-parts, a part, or few parts per million they still require, in many instances, that a null point be determined where the bridge is balanced. However, this becomes increasingly difficult within electrically noisy environments, with modern digital multimeters, and where the desired measurement point within the electrical system is physically difficult to access particularly when improved accuracy in calibration, standards, and measurements on circuits and components means measurement systems must operate at 50 parts per billion (ppb) and below. In order to address this, a null detector design is provided supporting operation within such electrically noisy environments with physical separation of the null detector measurement circuit from the electrical test equipment.

An electrical voltage measurement device, comprising at least one microelectromechanical device comprising a semitransparent material element with a variable refractive index n according to an electrical voltage applied to the element, a first electrode connectable to an anode of an electrical voltage source and electrically connected to a first point of the semitransparent material element, a second electrode connectable to a cathode of the electrical voltage source and electrically connected to a second point of the semitransparent material element, wherein the semitransparent material element is configured to receive an electrical voltage from the electrical voltage source through the first electrode and/or the second electrode, causing a variation ?n(V) in the refractive index n proportionally to the electrical voltage; and an optical device.

An electrical voltage values measuring device having at least one microelectromechanical device comprising a first electrode connectable to an anode of an electrical voltage source and a second electrode connectable to a cathode of the electrical voltage source, wherein the microelectromechanical device is configured to receive an electrical voltage from the electrical voltage source causing a deviation of the first electrode, associated with the electrical voltage, wherein the deviation causes a distance variation between the first electrode and the second electrode, and an optical processor that comprises a laser and an optical sensor.

An electrical voltage values measuring device having at least one microelectromechanical device comprising a first electrode connectable to an anode of an electrical voltage source and a second electrode connectable to a cathode of the electrical voltage source, wherein the microelectromechanical device is configured to receive an electrical voltage from the electrical voltage source causing a deviation of the first electrode, associated with the electrical voltage, wherein the deviation causes a distance variation between the first electrode and the second electrode, and an optical processor that comprises a laser and an optical sensor.

The optical interferometric sensor device comprises an integrated beam splitter having a first facet and a second facet with optical ports arranged therein. On the beam splitter, the beam splitting junctions as well as the optoelectronics-side ports and the sensing-side port are arranged with a mutual displacement along the direction of the first facet. This displacement reduces undesired interference effects caused by stray light. Also, a quarter-wave retarder is provided in a recess of the beam splitter with layers of soft adhesive adjacent to it in order to reduce stress.