Optical techniques and sensor devices for sensing or measuring electric currents and/or temperature based on photonic sensing techniques in optical reflection modes by using optical dielectric materials exhibiting Faraday effects are provided in various configurations. The disclosed optical sensing technology uses light to carry and transmit the current or temperature information obtained at the sensing location to a remote base station and this optical transmission allows remote sensing in various applications and provide a built-in temperature calibration mechanism to enhance the measurement accuracy in a range of different temperature conditions.

A system implementing fiber optics to monitor pipeline cathodic protection systems includes a cathodic protection system coupled to a hydrocarbon pipeline and a fiber optic system connected to the cathodic protection system. The cathodic protection system passes a current through the hydrocarbon pipeline to control corrosion of the hydrocarbon pipeline. The fiber optic system measures the current flowing through the hydrocarbon pipeline over time and provides the measured current.

The present invention relates to a device (1) for measuring a magnetic field (B) and/or an electric field (E) comprising:—a measurement cell (3) enclosing a gas that is sensitive to the Zeeman effect and/or to the Stark effect, a polarised light source (7) the wavelength of which is tuned to an absorption line of the gas that is sensitive to the Zeeman effect and/or to the Stark effect,—at least one polarimetry system (11) configured to measure a first parameter corresponding to the rotation by a polarisation angle caused by the passage of the beam (9) through the measurement cell (3) enclosing a gas that is sensitive to the Zeeman effect and/or to the Stark effect,—a system (13) for measuring absorption, configured to measure a second parameter corresponding to the absorption of the beam (9) by the gas that is sensitive to the Zeeman effect and/or to the Stark effect in the measurement cell (3), and a processing unit (15) configured to combine the measurement of the first parameter corresponding to the rotation by the polarisation angle and the absorption measurement in order to extract therefrom a third and/or fourth parameter corresponding respectively to an electric field (E) and/or a magnetic field (B) to be measured.

An optical current monitor for detecting a current traveling through conductive material. The optical current monitor comprises a light source for emitting light at an output level; a lens configured to receive the light; Faraday material positioned near the conductive material and configured to receive light that has passed through the lens, thereby producing rotated light; a polarizer configured to polarize the rotated light; a photodetector configured to receive the rotated light and output a signal as a function of the rotated light; and a feedback system. The feedback system is configured to receive the signal from the photodetector and modify the output level of the light source based on the signal so that the signal remains at a reference level when the current is not traveling through the conductive material.

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.

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.

A device for installing an all fiber optoelectrical transducer on the base of a pin insulator column, such that the device mounts to the insulator pin column in a bushing style of concentric attachment and enables retrofits of said device to existing transmission & distribution bushing insulator equipment. A rigid and solid mechanical support region contains a hollow bushing attachment point at a center location, and radiates outward and bonds solidly and statically to a hollow toroidal conduit, which houses optical wave guides, terminating at auxiliary connection ports, located on the exterior of the hollow toroidal conduit region, while hollow conduit support arms extend from the exterior conduit ring to a power conductor region, and integrate with optical connection ports located on static support stands, where the optical ports interface with a detachable and flexible fiber loop transducer, which surrounds an energized power conductor.

This patent document discloses techniques and devices for sensing or measuring electric currents and/or temperature based on photonic sensing techniques. The optical sensors for sensing the current or temperature can be configured as a polarization-insensitive optical sensor in either an optical transmissive configuration or an optical reflective configuration.

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.

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.