It is an object of the invention to improve processes, apparatuses and systems for measuring a measured variable. To this end, a measured variable is measured in a measuring process on the basis of an NV center as a quantum sensor. The NV center has a plurality of quantum states and is optically excitable on the basis of an occupancy of one of the quantum states into at least one excited state of the quantum states by means of an excitation light. The at least one excited state can decay at least with emission of emission light of the NV center. In the measuring process, the NV center is irradiated by the excitation light, the excitation light having a time periodic modulation, and a respective occupancy probability and/or a respective lifetime of the quantum states depending on the measured variable and the excitation light. A phase shift is determined between the emission light of the NV center and the modulation of the excitation light and a measurement value for the measured variable is determined on the basis thereof.

The present disclosure provides a biomagnetic field sensor system for diagnostic evaluation of a cardiac condition of an individual. The biomagnetic field sensor system may comprise an array of biomagnetic field sensors configured to sense an electromagnetic field associated with a heart of the individual and generate electromagnetic field data therefrom; a computer processor coupled to the array of biomagnetic field sensors; a memory configured to store the electromagnetic field data generated by the array of biomagnetic field sensors; and a non-transitory computer-readable medium encoded with a computer program including instructions that, when executed by the computer processor, cause the computer processor to receive the electromagnetic field data, and generate a diagnostic evaluation of a cardiac condition of the individual based at least in part on an analysis of the electromagnetic field data.

Nitrogen vacancy (NV) centers in diamond combine exceptional sensitivity with nanoscale spatial resolution by optically detected magnetic resonance (ODMR). Infrared (IR)-absorption-based readout of the NV singlet state transition can increase ODMR contrast and collection efficiency. Here, a resonant diamond metallodielectric metasurface amplifies IR absorption by concentrating the optical field near the diamond surface. This plasmonic quantum sensing metasurface (PQSM) supports plasmonic surface lattice resonances and balances field localization and sensing volume to optimize spin readout sensitivity. Combined electromagnetic and rate-equation modeling suggests a near-spin-projection-noise-limited sensitivity below 1 nT Hz.sup.−1/2 per μm.sup.2 of sensing area using numbers for contemporary NV diamond samples and fabrication techniques. The PQSM enables microscopic ODMR sensing with IR readout near the spin-projection-noise-limited sensitivity, making it appealing for imaging through scattering tissues and spatially resolved chemical NMR detection.

A microscope objective is disclosed comprising; a lens; a housing; a lens holder that is arranged to couple the lens to the housing; a first conductor and a second conductor, the first conductor and the second conductor extending along a sidewall of the housing, the first conductor and the second conductor being arranged to form at least one loop that is that is disposed about at least a portion of a perimeter of a field of view of the lens.

A microscope objective is disclosed comprising; a lens; a housing; a lens holder that is arranged to couple the lens to the housing; a first conductor and a second conductor, the first conductor and the second conductor extending along a sidewall of the housing, the first conductor and the second conductor being arranged to form at least one loop that is that is disposed about at least a portion of a perimeter of a field of view of the lens.

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.

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.

A three-axis vector optically pumped magnetometer includes a cell filled with an atomic gas subjected to an ambient magnetic field the projection of which on three rectangular coordinate axes defines three components thereof, and a photodetector arranged to receive a probe beam that passed through the cell. The photodetector includes a plurality of measurement units arranged in a plane transverse to a direction of propagation of the probe beam, the measurement units each providing a photodetection signal. The magnetometer further comprises a processing unit configured to determine, for each measurement unit and from the photodetection signal, a measurement associated with the measurement unit of each of the three components of the ambient magnetic field; calculate at least one difference between the measurements, associated with different measurement units, of a component of the magnetic field; and deliver a gradiometric measurement signal including the at least one difference calculated.

A three-axis vector optically pumped magnetometer includes a cell filled with an atomic gas subjected to an ambient magnetic field the projection of which on three rectangular coordinate axes defines three components thereof, and a photodetector arranged to receive a probe beam that passed through the cell. The photodetector includes a plurality of measurement units arranged in a plane transverse to a direction of propagation of the probe beam, the measurement units each providing a photodetection signal. The magnetometer further comprises a processing unit configured to determine, for each measurement unit and from the photodetection signal, a measurement associated with the measurement unit of each of the three components of the ambient magnetic field; calculate at least one difference between the measurements, associated with different measurement units, of a component of the magnetic field; and deliver a gradiometric measurement signal including the at least one difference calculated.

An illustrative system includes a brain interface system configured to be worn by a user and to output brain activity data representative of brain activity of the user while the user concurrently plays an electronic game and a computing device configured to obtain the brain activity data and modify, based on the brain activity data, an attribute of the electronic game.