1041results about "Magnetic field measurement using magneto-optic devices" patented technology

Provided are an atomic magnetometer and an operating method of the same. The atomic magnetometer includes a vapor cell receiving a circularly polarized pump beam and a linearly polarized probe beam and containing an alkali metal vapor, a detector adapted to receive the probe beam passing through the vapor cell to measure magneto-optical rotation of the probe beam, a feedback coil to establish a negative feedback magnetic field signal orthogonal to a first plane defined by traveling directions of the probe beam and the pump beam and provide the negative feedback magnetic field signal to the vapor cell, and a feedback amplifier adapted to provide feedback current to the feedback coil such that the negative feedback magnetic field proportional to a measurement magnetic field is established. The measurement magnetic field of a measurement target provides magneto-optical rotation of the probe beam in the vapor cell.

An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

High-accuracy magnetic measurement is performed by efficiently using nitrogen-vacancy pairs in all orientations. A magnetic measurement apparatus includes a diamond crystal and an image sensor. The diamond crystal has nitrogen-vacancy pairs. The image sensor detects the intensities of fluorescence generated by an exciting light applied to the diamond crystal by using a plurality of pixels. The nitrogen-vacancy pairs of the diamond crystal are made to one-to-one correspond to the pixels. The fluorescence generated by one nitrogen-vacancy pair is received by one pixel made to correspond to the nitrogen-vacancy pair.

A sensing probe may be formed of a diamond material comprising one or more spin defects that are configured to emit fluorescent light and are located no more than 50 nm from a sensing surface of the sensing probe. The sensing probe may include an optical outcoupling structure formed by the diamond material and configured to optically guide the fluorescent light toward an output end of the optical outcoupling structure. An optical detector may detect the fluorescent light that is emitted from the spin defects and that exits through the output end of the optical outcoupling structure after being optically guided therethrough. A mounting system may hold the sensing probe and control a distance between the sensing surface of the sensing probe and a surface of a sample while permitting relative motion between the sensing surface and the sample surface.

A magnetic measuring device can be downsized. The magnetic measuring device includes a diamond crystal, a microwave source, a light source array/microwave circuit chip, an image sensor, and a signal controller. The diamond crystal contains a plurality of nitrogen-vacancy pairs. The microwave source generates the microwave that is irradiated to the diamond crystal. The microwave circuit unit in the light source array/microwave circuit chip irradiates the diamond crystal with the microwave. The light source array in the light source array/microwave circuit chip irradiates the diamond crystal with excitation light. The image sensor detects an intensity of fluorescent light generated from the diamond crystal. The signal controller performs image processing of a fluorescent image taken-in by the image sensor, and controls operations of the light source array/microwave circuit chip and the microwave source. The light source array/microwave circuit chip is provided on a first surface side of the diamond crystal, and the image sensor is provided on a second surface side opposed to the first surface of the diamond crystal.

A magnetic field measurement system includes at least one magnetometer; and at least one flux concentrator made of a high magnetic permeability material and configured to receive magnetic field signals from a source, to concentrate the magnetic field signals or reorient the magnetic field signals in a preselected direction, and to direct the concentrated or reoriented magnetic field signals toward at least one of the at least one magnetometer. In addition to, or as an alternative to, the flux concentrator, the system can include a passive shield made of the high magnetic permeability material. The system may also include active shielding.

Providing: quickly brining a vapor cell 119 to a desired temperature when retaining the heat of the vapor cell 119 to enhance the magnetic field detection performance of an optically pumped magnetometer; preventing adherence of atoms in the vapor cell 119 to a laser irradiation light passing-through part of the vapor cell 119; downsizing the periphery of the vapor cell 119; and suppressing the effect of a magnetic field from a heater used to retain the heat of the vapor cell 119. The present invention includes: a transparent film heater 118 provided to a laser irradiation light passing-through part of a vapor cell 119, the vapor cell 119 being a magnetic detection part of the optically pumped magnetometer; a temperature detector 115 provided at a center part of a side of the vapor cell 119; a temperature regulator 111 that sets a desired temperature for heat retention of the vapor cell 119 and compares the desired temperature and the actual temperature of the vapor cell measured by the temperature detector 115; an operation unit 112 that upon receipt of a PID control signal for temperature control from the temperature regulator 111, performs a temperature adjustment and switches on/off, in a pulsed manner, current applied to the transparent film heater 118 after the desired temperature is reached; and a heater power supply 113 that upon receipt of an operation signal from the operation unit 112, applies current to the transparent film heater 118.

A magnetic field measurement system includes an array of magnetometers; at least one magnetic field generator with each of the at least one magnetic field generator configured to generate a first magnetic field at one or more of the magnetometers, wherein the generated first magnetic field combines with the ambient magnetic field to produce a directional magnetic field at the one or more of the magnetometers, where a magnitude and direction of the directional magnetic field is selectable using the at least one magnetic field generator; and a controller coupled to the magnetometers and the at least one magnetic field generator, the controller including a processor configured for receiving signals from the magnetometers, observing or measuring a magnetic field from the received signals, and controlling the at least one magnetic field generator to generate the first magnetic field and select the direction of the directional magnetic field.

A method of measuring at least one property including a magnetic property of target material is provided. The method includes the step of generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration The method further includes the step of irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material. The method still further includes the step of generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration. The method further includes the step of irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation. The method still further includes the step of electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses. The method further includes the step of detecting each modulated probe pulse to obtain one or more corresponding signals. The method still further includes the step of processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material.

The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

Provided are an inspection device and an inspection method capable of achieving improved magnetic field sensitivity by using a magnetic thin film of a small film thickness. A light-emitting unit 1 emits light of a first wavelength for acquiring magnetic field inspection information and a second wavelength for acquiring inspection object surface information. A selection unit 6 selects information from an inspection object 4 and information from a magnetophotonic crystal film 3 acquired by light irradiation performed by an irradiation unit 2. An image generation unit 9 generates image data based on the magnetic field inspection information acquired with the first wavelength and the inspection object surface information acquired with the second wavelength selected by the selection unit. Each of the generated image data is displayed on a display unit 10.

The invention discloses a microwave sensor based on an NV color center diamond. A diamond internally containing a Nitrogen-Vacancy color center is adopted as a sensitive element, electronic energy level stimulation is achieved through lasers, an additionally-arranged static magnetic field is scanned, and the microwave frequency and the microwave intensity are measured through fluorescence intensity detection. Dependency of electronic rabi-flopping of the NV color center in the diamond on the external microwave magnetic field is brought into play, high theoretical accuracy and good stability are achieved, the microwave sensor has the advantages of being small in size, low in cost, high in accuracy, large in temperature range, simple in operation condition and the like and rotates on the basis of solid atoms, and the microwave sensor can serve in all the fields with the requirements for the low-cost high-accuracy microwave frequency and intensity detection in the future.

The invention discloses a biaxial atomic spinning magnetometer. The biaxial atomic spinning magnetometer comprises an alkali metal gas chamber, non-magnetic electric heating equipment, a three-dimensional magnetic coil, a magnetic shielding layer, a pumping laser module and a detecting laser module. The alkali metal gas chamber is filled with alkali metal atoms, a quenching gas and a buffering gas; the non-magnetic electric heating equipment and the magnetic shielding layer enable the alkali metal atoms to work in a high-temperature and low-magnetic field environment, and ensure the alkali metal atoms in a non-spinning exchange relaxation state; the pumping laser module is used for polarizing the alkali metal atoms; the detecting laser module comprises two beams of independent detecting laser which are perpendicular to each other, and are used for sensing the magnetic field intensity in two directions which are perpendicular to each other simultaneously; measurement results are demodulated through a phase-locked amplifier. The biaxial atomic spinning magnetometer can acquire biaxial magnetic field information simultaneously through one alkali metal gas chamber, has the characteristics of high sensitivity, high integration degree and low cost, and has a wide application prospect in the fields of brain magnetic measurement, magnetocardiographic measurement and the like.

An array of optically pumped magnetometers includes a vapor cell arrangement having a wafer defining one or more cavities and alkali metal atoms disposed in the cavities to provide an alkali metal vapor; an array of light sources, each of the light sources arranged to illuminate a different portion of the one or more cavities of the vapor cell arrangement with light; at least one mirror arranged to reflect the light from the array of light sources after the light passes through the one or more cavities of the vapor cell arrangement; and an array of detectors to receive light reflected by the at least one mirror, wherein each of the detectors is arranged to receive light originating from one of the light sources.

In order to provide a magnetic field measuring apparatus facilitating the pressure control in a gas cell, or capable of inspecting the internal pressure of the gas cell without using any special process, the magnetic field measuring apparatus is configured such that a process layer of the magnetic field measuring apparatus has such a structure that includes a first hollow portion and a second hollow portion provided opposed to first hollow portion with a first isolation wall interposed therebetween. Alternatively, a method for manufacturing the magnetic field measuring apparatus includes breaking the first isolation wall after generating alkali metal (FIG. 17 and FIG. 20).

A light source unit irradiates a gas cell disposed in a measurement region with linearly polarized light in which the direction of travel is a z-axis direction and the vibration direction of an electric field is a y-axis direction. A polarimeter detects optical characteristics of light passing through the gas cell. A magnetic field generator applies an artificial magnetic field, capable of varying an x-axis component, a y-axis component, and a z-axis component, to the measurement region. A calculation control unit generates a plurality of artificial magnetic fields, calculates a magnetization value or a value corresponding to the magnetization value on the basis of the detection results of the polarimeter, and calculates an original magnetic field present in the measurement region, using an artificial magnetic field when the magnetization value or the value corresponding to the magnetization value satisfies a condition for external value.

Systems and apparatuses are disclosed for a hydrophone using a nitrogen vacancy center diamond magnetic sensor.

One embodiment is a magnetic field measurement system that includes at least one magnetometer having a vapor cell, a light source to direct light through the vapor cell, and a detector to receive light directed through the vapor cell; at least one magnetic field generator disposed adjacent the vapor cell; and a feedback circuit coupled to the at least one magnetic field generator and the detector of the at least one magnetometer. The feedback circuit includes at least one feedback loop that includes a first low pass filter with a first cutoff frequency. The feedback circuit is configured to compensate for magnetic field variations having a frequency lower than the first cutoff frequency. The first low pass filter rejects magnetic field variations having a frequency higher than the first cutoff frequency and provides the rejected magnetic field variations for measurement as an output of the feedback circuit.

An FM-NMOR magnetometer and concomitant magnetometry method comprising providing a linearly-polarized pump beam generator, employing a center wavelength approximately equal to a center wavelength of hyperfine peaks, and employing a modulation amplitude in the range HFS-3×LW to HFS.

A mutually calibrated magnetic imaging array system is described. The system includes a non-target magnetic source rigidly attached to a magnetometer, and an attached control unit to measure and adjust several parameters of a magnetic imaging array. A non-target magnetic field source is used to generate a well-defined and distinguishable spatial magnetic field distribution. The source is rigidly attached directly to a magnetometer, while the relative positions of the magnetometers are unknown. The magnetic imaging array is used to measure the strength of the non-target source magnetic fields and the information is used to calibrate several parameters of the array, such as, but not limited to, effective magnetometer positions and orientations with respect to each other and cross-talk between the magnetometers. The system, and method described herein eliminates the need for a separate calibration phantom.