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.

A physical state measurement apparatus includes a main solid material which generates fluorescence by excitation light from a light source part. A microwave application part applies microwaves to the main solid material so as to control an electron state of the main solid material. A detection part detects the physical state of an object to be measured by the fluorescence from the main solid material. A feedback part has a solid material for feedback and a control part and detects a difference in amplitude between operating points on a low-frequency side and a high-frequency side of a lowering portion of a spectrum amplitude centered on a resonance frequency of an electron spin resonance spectrum of fluorescence from the solid material for feedback and feedback-controls the microwave application part such that the difference becomes zero.

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 traffic monitoring system includes an electron spin defect magnetometer in a vicinity of a roadway, the electron spin defect magnetometer configured to detect magnetic field signals induced by transit entities in the vicinity of the roadway. The electron spin defect magnetometer includes an electron spin defect body including a plurality of lattice point defects, an optical source arranged to excite the plurality of lattice point defects, and a photodetector arranged to receive photoluminescence emitted by the plurality of lattice point defects.

A traffic monitoring system includes an electron spin defect magnetometer in a vicinity of a roadway, the electron spin defect magnetometer configured to detect magnetic field signals induced by transit entities in the vicinity of the roadway. The electron spin defect magnetometer includes an electron spin defect body including a plurality of lattice point defects, an optical source arranged to excite the plurality of lattice point defects, and a photodetector arranged to receive photoluminescence emitted by the plurality of lattice point defects.

Disclosed herein is a sensor chip for parallelized magnetic sensing of a plurality of samples, a system for parallelized magnetic sensing of a plurality of samples and a method for probing a plurality of samples using optically addressable solid-state spin systems. The sensor chip comprises an optically transparent substrate comprising a plurality of optically addressable solid-state spin systems arranged in a plurality of sensing regions in a surface layer below a top surface of the substrate. The sensor chip further comprises a plurality of sample sites, wherein each sample site is arranged above a respective sensing region. The sensor chip has a light guiding system configured to provide an optical path through the substrate connecting each of the sensing regions.

A magnetic field generator includes: an upper layer coil composed of a first conductive material and forming a loop circuit having a coil portion; a lower layer coil composed of a second conductive material and forming a loop circuit having a coil portion arranged opposite to the coil portion of the upper layer coil at a predetermined distance; and a substrate supporting the upper layer coil and the lower layer coil and having a dielectric material between the upper layer coil and the lower layer coil. High-frequency currents of opposite phases are passed through the upper layer coil and the lower layer coil, respectively, and a length per loop of the coil portion in the upper layer coil and the coil portion in the lower layer coil is matched to one wavelength of the high-frequency current.

A magnetic field generator includes: an upper layer coil composed of a first conductive material and forming a loop circuit having a coil portion; a lower layer coil composed of a second conductive material and forming a loop circuit having a coil portion arranged opposite to the coil portion of the upper layer coil at a predetermined distance; and a substrate supporting the upper layer coil and the lower layer coil and having a dielectric material between the upper layer coil and the lower layer coil. High-frequency currents of opposite phases are passed through the upper layer coil and the lower layer coil, respectively, and a length per loop of the coil portion in the upper layer coil and the coil portion in the lower layer coil is matched to one wavelength of the high-frequency current.

A magnetic field measuring device includes: a first cell and a second cell in which alkali metal atoms are entrapped and which are disposed in this order in a sensing direction of a magnetic field; a first reflective mirror, a second reflective mirror, and an autocollimator as an optical axis detector. Beam light as second polarized light and beam light as fourth polarized light, which are detected by the autocollimator, have orientations of optical axes in the same direction.

A magnetic field measuring device includes: a first cell and a second cell in which alkali metal atoms are entrapped and which are disposed in this order in a sensing direction of a magnetic field; a first reflective mirror, a second reflective mirror, and an autocollimator as an optical axis detector. Beam light as second polarized light and beam light as fourth polarized light, which are detected by the autocollimator, have orientations of optical axes in the same direction.