In order to carry out the polarimetric detection of a measurand, light of two polarization states is passed through a sensing element, where the two states suffer a differential phase shift depending on the value of the measurand. In order to compensate for only imperfections of the device, a method is proposed that is based on calibration values obtained in a low-value regime of the measurand only. Yet the method can still be used for accurately determining higher values of the measurand.

Techniques for reducing interference with sensor (light) signals and measurement in polarimetric fiber optic sensors from undesired effects of current and vibrations on light signals carried in fiber optic cables are presented. A sensor system comprises a first depolarizer associated with a fiber optic cable and in proximity to a light source that provides a light signal to such cable. First depolarizer depolarizes the light signal to produce a first depolarized light signal output to another portion of the fiber optic cable that can be wrapped around or associated with a conductor cable or ground cable. To reduce undesired polarizing effects on the first depolarized light signal due to current or vibrations from the conductor cable or ground cable, the system comprises a second depolarizer that depolarizes the (re)polarized light signal to produce a second depolarized light signal suitable for use in sensing current or voltage after additional processing.

In order to carry out the polarimetric detection of a measurand, light of two polarization states is passed through a sensing element, where the two states suffer a differential phase shift depending on the value of the measurand. In order to compensate for only imperfections of the device, a method is proposed that is based on calibration values obtained in a low-value regime of the measurand only. Yet the method can still be used for accurately determining higher values of the measurand.

Embodiments of the invention include a current sensing device for sensing current in an organic substrate. The current sensing device includes a released base structure that is positioned in proximity to a cavity of the organic substrate and a piezoelectric film stack that is positioned in proximity to the released base structure. The piezoelectric film stack includes a piezoelectric material in contact with first and second electrodes. A magnetic field is applied to the current sensing device and this causes movement of the released base structure and the piezoelectric stack which induces a voltage (potential difference) between the first and second electrodes.

Optical fiber-based measuring equipment for measuring the current circulating through at least one conductor. The measuring equipment includes an interrogator and a sensing portion connected to the interrogator and configured for being arranged in the proximity of the conductor. The sensing portion includes a first input branch and a second input branch coupled by means of a splitter to a first sensing branch and to a second sensing branch. The first sensing branch includes a first optical fiber winding arranged in the proximity of the conductor, and the second sensing branch includes a second optical fiber winding arranged in the proximity of the conductor, the first optical fiber winding and the second optical fiber winding having the same number of turns that are, however, wound in opposite directions.

A method for measuring the current circulating through at least one conductor with the use of optical fiber-based measuring equipment is provided. According to one implementation the measuring equipment includes a first emitter that emits a first signal which reaches a sensing branch through a first branch, runs through the sensing branch, and is modified depending on the current circulating through the conductor. A modified first signal is received by a second receiver from a second branch. A second emitter emits a second signal which reaches the sensing branch through the second branch, runs through the sensing branch, and is modified depending on the current circulating through the conductor. A modified second signal is received by a first receiver from the first branch. The current circulating through the conductor is determined by combining the modified first signal and the modified second signal.

A measurement system for real-time visualization of radiation pattern is provided. The measurement system comprises an antenna array with a plurality of antennas configured to provide a voltage gain corresponding to a received radio signal. Furthermore, the measurement system comprises a plurality of radio frequency detectors configured to rectify the voltage gain from each antenna of the plurality of antennas. In addition, the measurement system comprises a plurality of amplifiers downstream of the plurality of radio frequency detectors configured to amplify the magnitude of a rectified voltage from each of the radio frequency detectors. The measurement system moreover comprises a plurality of receiving elements, each includes a light emitting diode and configured to receive an amplified voltage corresponding to each amplifier of the plurality of amplifiers.

A non-invasive method of detecting electrical activity in a target volume. The method can comprise aiming a plurality of antennas at one or more target sub-volumes within a target volume and acquiring the radio signal created when an electrical discharge occurs. The method can then comprise processing the radio signals to determine the electrical activity within the target volume and displaying the electrical activity in the target volume.

A fiber-optic current sensor includes an opto-electronics module, a sensor head and a connecting fiber connecting the opto-electronics module to the sensor head. The sensor includes a first and a second beam splitter, between which the measuring light runs in two branches. One fiber connector is arranged in each branch, for connecting a cable assembly to the opto-electronics module. The optical path lengths between the two connectors and the second beam splitter are different, such that light waves cross-coupled into an orthogonal polarization mode due to angular misalignment of the connectors become incoherent with the non-cross-coupled waves returning from the sensor head.

A Faraday-based polarization scrambler is disclosed. The Faraday-based polarization scrambler may comprise a first toroidal assembly. The first toroidal assembly may include an optical fiber that is looped to form a first looped portion, and a first electrical wire that coils around the first looped portion to form a first toroidal configuration. In some examples, the first electrical wire may be connected to a voltage source and carries a current to form a magnetic field within the first toroidal configuration. In some examples, there may be additional toroidal assemblies provided to the Faraday-based polarization scrambler. One or more of these toroidal assemblies may create an actuation field to effect modulation for polarization scrambling and emulation that mitigates polarization-dependent effects.