Patent classifications
G01N24/006
NESTED AND PARALLEL FEEDBACK CONTROL LOOPS FOR ULTRA-FINE MEASUREMENTS OF MAGNETIC FIELDS FROM THE BRAIN USING A NEURAL DETECTION SYSTEM
An actuated magnetic field is generated at a plurality of distinct frequencies that at least partially cancels an outside magnetic field at the plurality of distinct frequencies, thereby yielding a total residual magnetic field. The total residual magnetic field is coarsely detected and a plurality of coarse error signals are respectively output. The total residual magnetic field is finely detected and a plurality of fine error signals are respectively output. The actuated magnetic field is controlled respectively at the plurality of distinct frequencies at least partially based on at least one of the plurality of coarse error signals, and finely controlled respectively at the plurality of distinct frequencies at least partially based on at least one of the plurality of fine error signals.
Atomic interferometer system
An atom interferometer system includes a sensor cell comprising alkali metal atoms. An optical system generates first and second interrogation beams having respective first and second frequencies and a circular polarization. The optical system includes optics that provide the first and second interrogation beams through the sensor cell in a first direction and reflect the first and second interrogation beams back through the sensor cell in a second direction opposite the first direction and in a same circular polarization to drive the alkali metal atoms from a first energy state to a greater energy state during an interrogation stage of sequential measurement cycles. A detection system detects a state distribution of a population of the alkali metal atoms between the first energy state and the second energy state during the interrogation stage based on an optical response.
Component Analysis Apparatus and Component Analysis Method
To provide an optical nuclear magnetic resonance apparatus in which a cleaning mechanism that can be mounted on an apparatus for performing an optical magnetic resonance method and can remove deposits on a sensor surface is mounted, and removal of contamination of the sensor surface can be determined. In a component analysis apparatus according to the present invention, a sensor includes therein a defect having an electron spin that causes electron spin resonance, an orientation of the electron spin can be optically detected, and an ozone generation device and an oxygen radical generation device are driven during washing of the sensor.
MAGNETIC FIELD MEASUREMENT APPARATUS AND MAGNETIC FIELD MEASUREMENT METHOD
An ODMR member is arranged in a measurement target AC magnetic field. A coil applies a magnetic field of a microwave to the ODMR member. A high frequency power supply causes the coil to conduct a current of the microwave. An irradiating device irradiates the ODMR member with light. A light receiving device detects light that the ODMR member emits. A measurement control unit performs a predetermined DC magnetic field measurement sequence at a predetermined phase of the measurement target AC magnetic field, and in the DC magnetic field measurement sequence, controls the high frequency power supply and the irradiating device and thereby determines a detection light intensity of the light detected by the light receiving device. A magnetic field calculation unit calculates an intensity of the measurement target AC magnetic field on the basis of the predetermined phase and the detection light intensity.
Neural feedback loop filters for enhanced dynamic range magnetoencephalography (MEG) systems and methods
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.
Magnetometry Based on Electron Spin Defects
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.
Magnetic field measurement apparatus and magnetic field measurement method
An ODMR member is arranged in a measurement target AC magnetic field. A coil applies a magnetic field of a microwave to the ODMR member. A high frequency power supply causes the coil to conduct a current of the microwave. An irradiating device irradiates the ODMR member with light. A light receiving device detects light that the ODMR member emits. A measurement control unit performs a predetermined DC magnetic field measurement sequence at a predetermined phase of the measurement target AC magnetic field, and in the DC magnetic field measurement sequence, controls the high frequency power supply and the irradiating device and thereby determines a detection light intensity of the light detected by the light receiving device. A magnetic field calculation unit calculates an intensity of the measurement target AC magnetic field on the basis of the predetermined phase and the detection light intensity.
MAGNETOMETRY BASED ON ELECTRON SPIN DEFECTS
A magnetometer includes a sample signal device; a reference signal device; a microwave field generator operable to apply a microwave field to the sample signal device and the reference signal device; an optical source configured to emit light including light of a first wavelength that interacts optically with the sample signal device and with the reference signal device; at least one photodetector arranged to detect a sample photoluminescence signal including light of a second wavelength emitted from the sample signal device and a reference photoluminescence signal including light of the second wavelength emitted from the reference signal device, in which the first wavelength is different from the second wavelength; and a magnet arranged adjacent to the sample signal device and the reference signal device.
CONTROLLING ALKALINE EARTH ATOMS FOR QUANTUM COMPUTING AND METROLOGY APPLICATIONS
An apparatus for individually trapping atoms, individually imaging the atoms, and individually cooling the atoms to prevent loss of the atoms from the trap caused by the imaging. The apparatus can be implemented in various quantum computing, sensing, and metrology applications (e.g., in an atomic clock).
METHODS AND SYSTEMS FOR FAST FIELD ZEROING FOR MAGNETOENCEPHALOGRAPHY (MEG)
A method of operating an optically pumped magnetometer (OPM) includes directing a light beam through a vapor cell of the OPM including a vapor of atoms; applying RF excitation to cause spins of the atoms to precess; measuring a frequency of the precession; for each of a plurality of different axes relative to the vapor cell, directing a light beam through the vapor cell, applying a magnetic field through the vapor cell along the axis, applying RF excitation to cause spins of the atoms to precess, and measuring a frequency of the precession in the applied magnetic field; determining magnitude and components of an ambient background magnetic field along the axes using the measured frequencies; and applying a magnetic field based on the components around the vapor cell to counteract the ambient background magnetic field to facilitate operation of the OPM in a spin exchange relaxation free (SERF) mode.