The invention concerns a method for nonperturbative detection of one or more magnetic inhomogeneities resulting from nano-defects in a single longitudinal anisotropic magnetic sample structure having a nanometric cross-sectional dimension. A solid-state lattice with a single spin defect is used for magnetometry assessment of the anisotropic magnetic sample structure to determine quantitative information concerning minor defects and inconsistencies in the sample structure.

A light-trapping geometry enhances the sensitivity of strain, temperature, and/or electromagnetic field measurements using nitrogen vacancies in bulk diamond, which have exterior dimensions on the order of millimeters. In an example light-trapping geometry, a laser beam enters the bulk diamond, which may be at room temperature, through a facet or notch. The beam propagates along a path inside the bulk diamond that includes many total internal reflections off the diamond's surfaces. The NVs inside the bulk diamonds absorb the beam as it propagates. Photodetectors measure the transmitted beam or fluorescence emitted by the NVs. The resulting transmission or emission spectrum represents the NVs' quantum mechanical states, which in turn vary with temperature, magnetic field strength, electric field strength, strain/pressure, etc.

A magnetic measurement device has a magnetic sensor including a glass cell having alkali metal gas encapsulated therein that is configured to detect a magnetic field using a magneto-optical characteristic of spin-polarized alkali metal. A laser light source is configured to generate pump light introduced into the magnetic sensor and a coil provided in the same magnetically shielded space as the magnetic sensor is configured to apply a static magnetic field and a RF magnetic field to the magnetic sensor. A signal processor is configured to perform lock-in detection of a light detection signal transmitted through the glass cell of the magnetic sensor, control an intensity of the static magnetic field and a frequency of the RF magnetic field generated by the coil according to a lock-in detection output, and obtain a measurement signal reflecting a magnetic field intensity of an object to be measured in the magnetically shielded space.

Various embodiments comprise a magnetic field compensation system. In some examples, the system comprises one or more coil drivers, magnetic field coils, and one or more magnetic field sensors. The one or more coil drivers supply a current to the magnetic field coils to generate a magnetic field. The magnetic field coils receive the current and generate the magnetic field. The magnetic field coils may be arranged in an array. The magnetic field coils individually comprise at least one coil trace pattern that encloses an area. The one or more magnetic field sensors measure the magnetic field generated by the magnetic field coils at a location proximate to the magnetic field coils.

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, h) methods for testing these systems, and i) a musical instrument as an example of an ultimate application of all these devices and methods.

A scalar magnetometer includes a sensor element, a circuit carrier, a pump radiation source, a radiation receiver and evaluation means. The pump radiation source emits pump radiation. The sensor element preferably includes one or more NV centers in diamond as paramagnetic centers. This paramagnetic center emits fluorescence radiation when irradiated with pump radiation. The radiation receiver converts a intensity signal of the fluorescence radiation into a receiver output signal. The evaluation means detects and/or stores and/or transmits the value of the receiver output signal. The material of the circuit carrier is preferably transparent for the pump radiation in the radiation path between pump radiation source and sensor element and transparent for the fluorescence radiation in the radiation path between sensor element and radiation receiver. The components sensor element, pump radiation source, radiation receiver and evaluation means are preferably mechanically attached to the circuit carrier.

A zero-field paramagnetic resonance magnetometer (ZF-PRM) system and method for quickly and efficiently finding and optimizing the zero-field (ZF) resonance is described. In this system and method a magnetic coil is used to apply a magnetic bias field in the direction of the pump beam to artificially broaden the width and maximize the strength of the ZF resonance. By making the ZF resonance easy to detect, the ZF resonance may be found quickly found without the use of additional components and complex algorithms. Once the ZF resonance is found, a compensating magnetic field can be applied to null the magnetic field in the vicinity of the vapor cell in the ZF-PRM, thereby initializing it for operation.

Sensors and methods are provided that include a diamond material containing a nitrogen vacancy center, the diamond material being configured to be exposed to an environment comprising one or more gases, an optical light source configured to excite the nitrogen vacancy center of the diamond material with an optical light beam produced therefrom, a detector configured to detect a signal originating from the diamond material in response to the optical light beam exciting the nitrogen vacancy center, and the capability of analyzing the signal to identify a specific gas in the environment. Also included are levitated spin-optomechanical systems capable of elevating in a vacuum a diamond material containing a nitrogen vacancy center, applying microwave radiation to the diamond material for controlling and flipping the electron spin of the nitrogen vacancy center, and monitoring electron spin of the nitrogen vacancy center.

A light receiving device receives fluorescence emitted by a magnetic resonance member in response to excitation light and generates a fluorescence sensor signal corresponding to a fluorescence intensity. A CMR arithmetic part performs common mode rejection with respect to the fluorescence sensor signal based on a reference light sensor signal of reference light that is obtained by branching the excitation light in consideration of nonlinearity of a level of the fluorescence sensor signal corresponding to an amount of the excitation light and generates a CMR signal. An A/D converter digitizes the CMR signal. An analog/digital converter digitizes the reference light sensor signal. An arithmetic processing device derives a measurement value of a measured field based on the digitized CMR signal and the digitized reference light sensor signal.

A current sensor includes a magnetometer. The magnetometer includes a sensor element including at least one paramagnetic center that generates fluorescence radiation, a radiation receiver configured to receive the fluorescence radiation from the sensor element and generate a first electrical signal based on receiving the fluorescence radiation from the sensor element, and an electronic output circuit configured to generate and output a second electrical signal based on the first electrical signal. The value of the fluorescence radiation generated by the sensor element depends in part on a magnetic flux density at the location of the sensor element. The magnetometer is configured to be placed near or in direct contact to a wire carrying a current such that the current in the wire modifies the magnetic flux density at the location of the sensor element.