Abstract: A light intensity modulator includes an input optical fiber; an output optical fiber; an optical arrangement having a lens, where the optical arrangement is configured to receive light from the input optical fiber, pass the light through the lens, and direct the light to the output optical fiber; and a piezoelectric device coupled to the lens, where the piezoelectric device is configured for moving the lens to alter overlap of the output optical fiber and the light directed to the output optical fiber to modulate intensity of light in the output optical fiber.

Abstract: A magnetic field recording system includes a headgear to be placed on a user; optically pumped magnetometers (OPMs) disposed in or on the headgear to detect magnetic fields; at least two sensing modalities selected from the following: i) a magnetic sensing modality, ii) an optical sensing modality, or iii) an inertial sensing modality; and a tracking unit configured to receive, from each of the at least two sensing modalities, a corresponding magnetic data stream, optical data stream, or inertial data stream and to track a position or orientation of the headgear or user; and a system controller configured to control operation of the OPMs and to receive, from the tracking unit, the position or orientation of the headgear or user.

Abstract: A magnetic field measurement system includes a magnetometer having at least one vapor cell, at least one light source to direct at least two light beams through the vapor cell(s), and at least one detector; at least one magnetic field generator to modify an external magnetic field experienced by the vapor cell(s); and at least one processor configured for: applying a first modulation pattern, bmod(t), to the magnetic field generator(s) to modulate a magnetic field at the vapor cell(s), where bmod(t)=[cx cos(?t)+sx sin(?t), cy cos(?t)+sy sin(?t), cz cos(?t)+sz sin(?t)], where cx, sx, cy, sy, cz, and sz are amplitudes and ? is a frequency; directing the light source(s) to direct the light beams through the vapor cell(s); receiving signals from the detector(s); and determining three orthogonal components of the external magnetic field using the received signals. Multi-frequency modulation patterns can alternatively be used.

Abstract: A magnetic field measurement system includes a magnetometer having at least one vapor cell, at least one light source to direct at least two light beams through the vapor cell(s), and at least one detector; at least one magnetic field generator to modify an external magnetic field experienced by the vapor cell(s); and at least one processor configured for: applying a first modulation pattern, bmod(t), to the magnetic field generator(s) to modulate a magnetic field at the vapor cell(s), where bmod(t)=[cx cos(?t)+sx sin(?t), cy cos(?t)+sy sin(?t), cz cos(?t)+sz sin(?t)], where cx, sx, cy, sy, cz, and sz are amplitudes and ? is a frequency; directing the light source(s) to direct the light beams through the vapor cell(s); receiving signals from the detector(s); and determining three orthogonal components of the external magnetic field using the received signals. Multi-frequency modulation patterns can alternatively be used.

Abstract: A magnetic field measurement system includes a light source that emits a light beam; an optical fiber to transmit the light beam; a variable optical attenuator to increase stability of an intensity of the light beam; a beam splitter to divide the light beam into an OPM light beam and a monitor light beam; a monitor detector to detect the monitor light beam and generate a monitor signal; a vapor cell with alkali metal atoms disposed therein and configured for transmission of the OPM light beam through the vapor cell; an OPM detector to detect the OPM light beam after transmission through the vapor cell and generate an OPM signal; and a group delay filter to combine the monitor signal and the OPM signal to generate a reduced noise OPM signal, where the group delay filter accounts for a phase difference between the monitor signal and the OPM signal.

Abstract: 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.

Abstract: A light intensity modulator includes an input optical fiber; an output optical fiber; an optical arrangement having a lens, where the optical arrangement is configured to receive light from the input optical fiber, pass the light through the lens, and direct the light to the output optical fiber; and a piezoelectric device coupled to the lens, where the piezoelectric device is configured for moving the lens to alter overlap of the output optical fiber and the light directed to the output optical fiber to modulate intensity of light in the output optical fiber.

Abstract: A magnetic field recording system includes a headgear to be placed on a user; optically pumped magnetometers (OPMs) disposed in or on the headgear to detect magnetic fields; at least two sensing modalities selected from the following: i) a magnetic sensing modality, ii) an optical sensing modality, or iii) an inertial sensing modality; and a tracking unit configured to receive, from each of the at least two sensing modalities, a corresponding magnetic data stream, optical data stream, or inertial data stream and to track a position or orientation of the headgear or user; and a system controller configured to control operation of the OPMs and to receive, from the tracking unit, the position or orientation of the headgear or user.

Abstract: 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.