Embodiments relate to a sensor system configured to detect physical rotation, entire or relative, of one or more objects and/or their environment and/or proximity of a magnetic field, by measuring the degree of localization of a medium trapped in a ring-shaped artificial lattice. The lattice structure can be configured to comprise of lattice sites distributed with a lattice period around an azimuth of a closed ring. The site depths of the plurality of lattice sites can be configured to be modulated with a modulation period different from the lattice period to affect the onsite energies of each lattice site and the eigenstates of the system. Physical rotation of the sensor and/or the proximity of magnetic field will alter the localization properties so as to cause the degree of localization of the medium to change (e.g., the medium becomes more confined in space or more spread out in space).

A fibre optic cable structure (300) suitable for fibre optic sensing with an improved sensitivity to an environmental parameter is described. The structure (300) includes an optical fibre (301) and a bend inducer (304) responsive to the environmental parameter to control bending of the optical fibre. The bend inducer (304) is configured to adopt a first configuration, that induces a first curvature of the optical fibre, at a first value of the environmental parameter and to adopt a second configuration at a second, different, value of the environmental parameter that induces a second, different, curvature of the optical fibre. By action of the bend inducer (304) a change in value of the environmental parameter imparts a bending force on the optical fibre.

A sensor system is based on diamonds with a high density of NV centers. The description includes a) methods for producing the necessary diamonds of high NV center density, b) characteristics of such diamonds, c) sensing elements for utilizing the fluorescence radiation of such diamonds, d) sensing elements for utilizing the photocurrent of such diamonds, e) systems for evaluating these quantities, f) reduced noise systems for evaluating these systems, g) enclosures for using such systems in automatic placement equipment, g) methods for testing these systems, and h) a musical instrument as an example of an ultimate application of all these devices and methods.

A magnetometer includes a diamond sensor, an excitation light source, a diamond sensor case, and a photodiode. The excitation light source irradiates the diamond sensor case with excitation light. In the diamond sensor case, a reflection film which reflects excitation light is formed on either a front surface or an inner surface, and the diamond sensor is stored. The photodiode detects intensity of fluorescence generated from the diamond sensor. The diamond sensor case includes a fluorescence output window and an excitation-light reception window. Fluorescence generated by the diamond sensor is output through the fluorescence output window. Excitation light emitted by the excitation light source is received through the excitation-light reception window. The photodiode is provided on a side of a second surface opposite to a first surface which is a magnetism measurement surface of the diamond sensor.

Systems and methods for imaging characteristics of a sample and for identifying regions of damage in the sample are generally described. Some example systems and methods for non-destructive evaluation of regions of material may operate in a direct current (DC) mode in which the system directly images regions of material where weak structural damage has occurred by imaging a self magnetic field generated by a DC electric current coupled through the material. Some example systems may operate in an alternating current (AC) mode to image regions of material where damage has occurred by generating a time varying magnetic field due to AC excitation coils inducing eddy currents in the sample, and imaging a magnetic field generated by the eddy currents around the regions of damage. The systems may use magneto-optical imaging techniques (MOI) to measure and map the magnetic field and channels of current flow in the material, for example.

Systems and methods for imaging characteristics of a sample and for identifying regions of damage in the sample are generally described. Some example systems and methods for non-destructive evaluation of regions of material may operate in a direct current (DC) mode in which the system directly images regions of material where weak structural damage has occurred by imaging a self magnetic field generated by a DC electric current coupled through the material. Some example systems may operate in an alternating current (AC) mode to image regions of material where damage has occurred by generating a time varying magnetic field due to AC excitation coils inducing eddy currents in the sample, and imaging a magnetic field generated by the eddy currents around the regions of damage. The systems may use magneto-optical imaging techniques (MOI) to measure and map the magnetic field and channels of current flow in the material, for example.

A magnetic field recording system includes a headgear for a user; optically pumped magnetometers (OPMs) disposed in or on the headgear to detect magnetic fields and, in response to the detection, produce magnetic field data; at least one sensing modality including an optical sensing modality having at least one light source and at least one camera or light detector to receive light reflected or directed from the user and to produce an optical data stream; a tracking unit to receive the optical data stream and track a position or orientation of the headgear or user; a system controller to control operation of the OPMs and receive, from the tracking unit, the position or orientation of the headgear or user; and a processor to receive the optical data stream and the magnetic field data from the OPMs and analyze the magnetic field data using the optical data stream for validation.

This disclosure is directed to fiber optic pulsed polarimeters based on either streak camera or photodiode detection using a backscatter tailored optical fiber and the polarization optical time domain reflectometry technique for conducting remote diagnostic measurements of inducing fields along the fiber. The backscatter tailored optical fiber comprises a single mode fiber with an array of fiber Bragg gratings written to produce a predetermined distribution of backscatter signal in intensity and spectral content in response to a pulse propagating along the array. The fiber optic pulsed polarimeter includes a directional coupler that diverts the backscatter from the backscatter-tailored optical fiber to a polarization detection system for determining the polarization state of the backscatter as the polarized light pulse transits the backscatter-tailored optical fiber.

This disclosure is directed to fiber optic pulsed polarimeters based on either streak camera or photodiode detection using a backscatter tailored optical fiber and the polarization optical time domain reflectometry technique for conducting remote diagnostic measurements of inducing fields along the fiber. The backscatter tailored optical fiber comprises a single mode fiber with an array of fiber Bragg gratings written to produce a predetermined distribution of backscatter signal in intensity and spectral content in response to a pulse propagating along the array. The fiber optic pulsed polarimeter includes a directional coupler that diverts the backscatter from the backscatter-tailored optical fiber to a polarization detection system for determining the polarization state of the backscatter as the polarized light pulse transits the backscatter-tailored optical fiber.

Time-multiplexed atomic magnetometry uses first and second atomic vapor cells located adjacent to a sample to be measured. Each vapor cell operates according to a sequence of alternating pumping and probing stages. However, the sequences are temporally offset from each other such that the second vapor cell is pumped while the first vapor cell is probed, and the first vapor cell is pumped while the second vapor cell is probed. With this time-multiplexed operation, the magnetic field generated by the sample can be measured without any time gaps. The Hilbert transform of the signals may be taken to obtain their instantaneous phases, which may then be interleaved to form a single gapless time sequence that represents the magnetic field of the sample over a time window that lasts for several continuous pumping/probing stages.