A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring geomagnetic field at positions of the optically pumped magnetometers, magnetic sensors for measuring a fluctuating magnetic field at the positions of the optically pumped magnetometers, nulling coils for cancelling the geomagnetic field, and an active shield coil for cancelling the fluctuating magnetic field; an MRI apparatus including nulling coils for applying a static magnetic field and a gradient magnetic field, a transmission coil, and a receive coil; and a control device that, when measuring a brain's magnetic field, controls currents supplied to the nulling coils and the active shield coil based on measured values of the magnetic sensors and, when measuring an MR image, controls the static magnetic field and the gradient magnetic field by controlling currents supplied to the nulling coils and generates an MR image from an output of the receive coil.

A magnetoencephalograph M1 includes: multiple optically pumped magnetometers 1A that measure a brain's magnetic field; multiple magnetic sensors for geomagnetic field cancellation 2 that measure a magnetic field; multiple magnetic sensors for active shield 3 that measure a fluctuating magnetic field; a geomagnetic field nulling coil; an active shield coil 9; a control device 5 that determines a current to generate a magnetic field for canceling the magnetic field based on measured values of the multiple magnetic sensors for geomagnetic field cancellation 2, determines a current to generate a magnetic field for canceling the fluctuating magnetic field based on measured values of the multiple magnetic sensors for active shield 3, and outputs a control signal corresponding to each of the determined currents; and a coil power supply 6 that outputs a current to each coil in response to the control signal.

A magnetoencephalograph M1 includes: multiple pump-probe type optically pumped magnetometers 1A; a bias magnetic field forming coil 15 for applying a bias magnetic field in the same direction as a direction of pump light of each of the multiple pump-probe type optically pumped magnetometers 1A and in a direction approximately parallel to a scalp; a control device 5 that determines a current for the bias magnetic field forming coil and outputs a control signal corresponding to the determined current; and a coil power supply 6 that outputs a current to the bias magnetic field forming coil in response to the control signal output from the control device.

An optically pumped magnetometer 1 includes: a cell 2; a pump laser 7 that emits pump light; one or more pump light mirrors that cause the pump light guided in a first direction; a probe laser 8 that emits probe light; a splitting unit 12 that splits the probe light into multiple light components; one or more probe light mirrors that cause each of the probe light components guided in a second direction, which is a direction perpendicular to the first direction; a detection unit that detects each of the probe light components perpendicular to the pump light inside the cell 2; and a derivation unit that derives a magnetic field corresponding to a region where each of the probe light components and the pump light are perpendicular to each other based on a detection result of the detection unit.

A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring a static magnetic field at positions of the optically pumped magnetometers, and a nulling coil for canceling the static magnetic field; an MRI apparatus including a permanent magnet, a gradient magnetic field coil, a transmission coil, and a receive coil for detecting a nuclear magnetic resonance signal; and a control device that, when measuring the brain's magnetic field, controls a current to be supplied to the nulling coil based on measured values of the magnetic sensors and operates so as to cancel a static magnetic field at the position of each of the optically pumped magnetometers and, when measuring an MR image, controls the gradient magnetic field by controlling a current to be supplied to the gradient magnetic field coil and generates an MR image based on an output of the receive coil.

A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring a static magnetic field at positions of the optically pumped magnetometers, and a nulling coil for canceling the static magnetic field; an MRI apparatus including a permanent magnet, a gradient magnetic field coil, a transmission coil, and a receive coil for detecting a nuclear magnetic resonance signal; and a control device that, when measuring the brain's magnetic field, controls a current to be supplied to the nulling coil based on measured values of the magnetic sensors and operates so as to cancel a static magnetic field at the position of each of the optically pumped magnetometers and, when measuring an MR image, controls the gradient magnetic field by controlling a current to be supplied to the gradient magnetic field coil and generates an MR image based on an output of the receive coil.

Systems and methods for an integrated photonics quantum vector magnetometer are provided herein. In certain embodiments, a device includes a substrate; a radio frequency emitter that emits energy in a range of radio frequencies; and a waveguide layer formed on the substrate. The waveguide layer includes a first waveguide of a first material, wherein a probe laser is propagating within the first waveguide; and a second waveguide, wherein the second waveguide is positioned proximate to the first waveguide along a coupling length such that a pump laser propagating within the second waveguide is coupled into the first waveguide along the coupling length, wherein the pump laser causes the first material to absorb the probe laser at one or more frequencies in the range of frequencies. Moreover, the device includes a processing device that calculates a magnetic field strength based on an identification of the one or more frequencies.

Systems and methods for an integrated photonics quantum vector magnetometer are provided herein. In certain embodiments, a device includes a substrate; a radio frequency emitter that emits energy in a range of radio frequencies; and a waveguide layer formed on the substrate. The waveguide layer includes a first waveguide of a first material, wherein a probe laser is propagating within the first waveguide; and a second waveguide, wherein the second waveguide is positioned proximate to the first waveguide along a coupling length such that a pump laser propagating within the second waveguide is coupled into the first waveguide along the coupling length, wherein the pump laser causes the first material to absorb the probe laser at one or more frequencies in the range of frequencies. Moreover, the device includes a processing device that calculates a magnetic field strength based on an identification of the one or more frequencies.

Provided is a method of measuring a magnitude of magnetization of a perpendicular magnetic thin film, including: forming a stripe pattern in which a first magnetic domain that extends in a y direction and is magnetized in a z direction and a second magnetic domain that extends in the y direction and is magnetized in a direction opposite to the z direction are arranged alternately in an x direction, in a perpendicular magnetic thin film that extends in an xy plane; changing widths in the x direction, of the first and second magnetic domains by applying a magnetic field having a predetermined magnitude, in the z direction, to the perpendicular magnetic thin film; and calculating an absolute value of the magnetization of the perpendicular magnetic thin film on the basis of a ratio between the widths in the x direction, of the first magnetic domain and the second magnetic domain.

Provided is a method of measuring a magnitude of magnetization of a perpendicular magnetic thin film, including: forming a stripe pattern in which a first magnetic domain that extends in a y direction and is magnetized in a z direction and a second magnetic domain that extends in the y direction and is magnetized in a direction opposite to the z direction are arranged alternately in an x direction, in a perpendicular magnetic thin film that extends in an xy plane; changing widths in the x direction, of the first and second magnetic domains by applying a magnetic field having a predetermined magnitude, in the z direction, to the perpendicular magnetic thin film; and calculating an absolute value of the magnetization of the perpendicular magnetic thin film on the basis of a ratio between the widths in the x direction, of the first magnetic domain and the second magnetic domain.