An optical waveguide for a magneto-optical current sensor. The optical waveguide includes a first end surface, through which light can be coupled into the optical waveguide, and a second end surface, through which light can be coupled out of the optical waveguide, wherein at least one of the two end surfaces has an anti-reflective coating.

A magnetic field sensor comprises a magnetically responsive light propagating component configured to cause a polarization of light propagating inside the component to be rotated in response to an applied magnetic field, wherein the magnetically responsive light propagating component is formed of a bulk material doped with a dopant, the dopant including at least gadolinium, the dopant concentration being at a sufficiently low concentration such that the dopant is uniformly dispersed in the bulk material to provide a high Verdet constant. The magnetic field sensor also comprises a detector, and a polarization-maintaining light input device to couple the light into the magnetically responsive light propagating component. The detector is configured to measure a property of light output from the magnetically responsive light propagating component to determine a change in polarization of the light, the change caused by the presence of a magnetic field.

An interference type optical magnetic field sensor device 1 has a light emitter 10 emitting first linearly polarized light, a first optical element 30 emitting a first linearly polarized wave and a second linearly polarized wave orthogonal to the first linearly polarized wave with respect to incident the first linearly polarized light, and emitting a second linearly polarized light with respect to incident third linearly polarized wave and a forth linearly polarized wave orthogonal to the third linearly polarized wave, a magnetic field sensor element 50 disposed at least a portion thereof within a predetermined magnetic field an optical path unit 40 connected to the first optical element and the magnetic field sensor element, and having a first optical path propagating the first linearly polarized wave and the forth linearly polarized wave, and a second optical path propagating the second linearly polarized wave and the third linearly polarized wave, a detection signal generator 60 outputting a detection signal by separating the second linearly polarized light into an S polarization component and a P polarization component, converting the S polarization component and the P polarization component into an electric signal, and an optical branching element 20 transmitting the first linearly polarized light to the first optical element, and branching the second linearly polarized light to the detection signal generator, wherein the magnetic field sensor element emits the first linearly polarized wave and the second linearly polarized wave as incident light, and emits the third linearly polarized wave with respect to the first linearly polarized wave and the forth linearly polarized wave with respect to the second linearly polarized wave as return light.

A magnetometer includes: a substrate; a diamond layer on the substrate, in which the diamond layer includes a defect sub-layer including multiple lattice point defects; a microwave field transmitter; an optical source configured to emit light including a first wavelength that excites the multiple lattice point defects from a ground state to an excited state; a photodetector arranged to detect photoluminescence including a second wavelength emitted from the defect sub-layer, in which the first wavelength is different from the second wavelength; and a magnet arranged adjacent to the defect sub-layer.

A film forming system for forming a magnetic film is provided. The film forming system includes a processing module configured to form the magnetic film on a substrate, a magnetization characteristic measuring device configured to measure magnetization characteristics of the magnetic film formed on the substrate in the processing module, and a transfer unit configured to transfer the substrate between the processing module and the magnetization characteristic measuring device. The magnetization characteristic measuring device includes a magnetic field applying mechanism having a permanent magnet magnetic circuit configured to apply a magnetic field to the substrate and adjust the magnetic field to be applied to the substrate, and a detector configured to detect magnetization characteristics of the substrate.

Disclosed is an optical fiber winding for measuring the current circulating through a conductor. According to one embodiment the optical fiber winding includes a central support core extending in a longitudinal direction, a first optical fiber cable arranged around the central support core, a second optical fiber cable arranged around the central support core, the first and second optical fiber cables extend in a helical manner around the central support core. According to one embodiment the first optical fiber cable is twisted about its longitudinal axis in a first twist direction, and the second optical fiber cable is twisted about its longitudinal axis in a second twist direction, the first twist direction being opposite the second twist direction. Optical fiber-based current measuring equipment 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).

An optical pumping magnetometer made with linearly polarised light. The magnetometer comprises a cell filled with an atomic gas and a detector configured to output a signal carrying information about an alignment state of atoms of the atomic gas in the cell. The magnetometer also comprises a collimator arranged to collimate a light beam before it illuminates the cell and a mirror arranged to reflect the collimated light beam after it has passed through the cell such that the collimated light beam makes a multipass through the cell and illuminates the same region of the cell several times.

A magnetic field measurement cable (10) of the present disclosure includes an electric cable (1) provided at an axial part, and an outer circumferential cable (2) provided on the outer side of the electric cable (1) and helically formed by a plurality of steel wires helically wound and a magnetic field measurement optical cable (3) having an optical fiber cable (3a).

A chip-type three-dimensional magnetic field sensor includes a light source (1), an input straight waveguide (2), a polarization beam splitting waveguide (3), a 1:1 power beam splitter (4), three 1:2 type Y waveguides, three 2:1 type Y waveguides, three output straight waveguides, three magneto-optical waveguides and three photodetectors. The light source (1) outputs broad-spectrum depolarized light into the input straight waveguide (2), and then the light is divided into TE (transverse electric) polarized light and TM (transverse magnetic) polarized light. The TE polarized light is divided into two beams of TE polarized branch light. The TM polarized light is divided into two beams of TM polarized branch light. One of the two beams of TM polarized branch light is divided into two beams of first TM polarized sub-branch light. Another of the two beams of TM polarized branch light is divided into two beams of second TM polarized sub-branch light.