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 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.

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.

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.

Methods and systems are disclosed for sensing an environment electric field. In one exemplary implementation, a method includes disposing a sensor in the environment, wherein the sensor comprising a crystalline lattice and at least one optically-active defect in the crystalline lattice; pre-exciting the crystalline lattice to prepare at least one defect in a first charge state using a first optical beam at a first optical wavelength; converting at least one defect from the first charge state to a second charge state using a second optical beam at a second optical wavelength; monitoring a characteristics of photoluminescence emitted from the defect during or after the conversion of the at least one defect from the first charge state to the second charge state; and determining a characteristics of the electric field in the environment according to the monitored characteristics of the photoluminescence.

Methods and systems are disclosed for sensing an environment electric field. In one exemplary implementation, a method includes disposing a sensor in the environment, wherein the sensor comprising a crystalline lattice and at least one optically-active defect in the crystalline lattice; pre-exciting the crystalline lattice to prepare at least one defect in a first charge state using a first optical beam at a first optical wavelength; converting at least one defect from the first charge state to a second charge state using a second optical beam at a second optical wavelength; monitoring a characteristics of photoluminescence emitted from the defect during or after the conversion of the at least one defect from the first charge state to the second charge state; and determining a characteristics of the electric field in the environment according to the monitored characteristics of the photoluminescence.

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.

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.

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.

To provide a magnetic sensor element and a magnetic sensor device that can be easily manufactured and can reduce a loss of light to the extent possible. The above-described problem is solved by a magnetic sensor element comprising a planar lightwave circuit (11) provided with a light branching part (12), an input optical fiber (19) and an output optical fiber (20) connected to the planar lightwave circuit (11), a metal magnetic body type light transmitting film (30) that is provided on one end surface of the planar lightwave circuit (11) and transmits light entered from the input optical fiber (19), and a reflecting film (40) that is provided on the metal magnetic body type light transmitting film (30) and reflects the transmitted light. The output optical fiber (20) is a polarization-plane maintaining optical fiber, and the input optical fiber (19) and the output optical fiber (20) are aligned and connected to the planar lightwave circuit (11).