A sensing probe may be formed of a diamond material comprising one or more spin defects that are configured to emit fluorescent light and are located no more than 50 nm from a sensing surface of the sensing probe. The sensing probe may include an optical outcoupling structure formed by the diamond material and configured to optically guide the fluorescent light toward an output end of the optical outcoupling structure. An optical detector may detect the fluorescent light that is emitted from the spin defects and that exits through the output end of the optical outcoupling structure after being optically guided therethrough. A mounting system may hold the sensing probe and control a distance between the sensing surface of the sensing probe and a surface of a sample while permitting relative motion between the sensing surface and the sample surface.

The invention is related to a sample holder for measurements of optically detected magnetic resonance, including a bottom plate, a top plate and a middle plate, wherein all the plates are made of a dielectric material. The top plate is provided with at least one top opening, enabling continuous optical access to the studied sample during measurements. The sample is placed in the central opening provided in the middle plate. The non-magnetic conductive strips provided on the surfaces of the bottom plate, the middle plate and the top plate ensure formation of an electrical circuit, which allows coupling of the studied sample with the generated microwave radiation to be achieved once the microwave sources is switched on. The invention also includes a sample holder for measurements of optically detected magnetic resonance, enabling formation of at least one loop of the electrical circuit.

Spin resonance spectroscopy and/or imaging is achieved using a system that combines longitudinal (e.g., along the z-axis) detection with a modulated fictitious field generated by a transverse plane (e.g., xy-plane) RF field. Based on z-axis detection of magnetization polarized by this fictitious field as it is modulated (e.g., modulated on and off, or otherwise), spin resonance signals (e.g., EPR, NMR) are measurable with high isolation simultaneous transmit and receive capability. Additionally or alternatively, spin relaxation times can be measured using the described systems.

Spin resonance spectroscopy and/or imaging is achieved using a system that combines longitudinal (e.g., along the z-axis) detection with a modulated fictitious field generated by a transverse plane (e.g., xy-plane) RF field. Based on z-axis detection of magnetization polarized by this fictitious field as it is modulated (e.g., modulated on and off, or otherwise), spin resonance signals (e.g., EPR, NMR) are measurable with high isolation simultaneous transmit and receive capability. Additionally or alternatively, spin relaxation times can be measured using the described systems.

Certain aspects of the present disclosure provide methods and apparatus for closed-loop control of a system using one or more electron paramagnetic resonance (EPR) sensors located on-site. With such EPR sensors, a change can be applied to the system, the EPR sensors can measure the effect(s) of the change, and then adjustments can be made in real-time. This feedback process may be repeated continuously to control the system.

Certain aspects of the present disclosure provide methods and apparatus for closed-loop control of a system using one or more electron paramagnetic resonance (EPR) sensors located on-site. With such EPR sensors, a change can be applied to the system, the EPR sensors can measure the effect(s) of the change, and then adjustments can be made in real-time. This feedback process may be repeated continuously to control the system.

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.

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 invention provides an apparatus and a corresponding method useful for electron paramagnetic resonance imaging, in situ and in vivo, using high-isolation transmit/receive (TX/RX) coils, which, in some embodiments, provide microenvironmental images that are representative of particular internal structures in the human body and spatially resolved images of tissue/cell protein signals responding to conditions (such as hypoxia) that show the temporal sequence of certain biological processes, and, in some embodiments, that distinguish malignant tissue from healthy tissue. In some embodiments, the TX/RX coils are in a surface, volume or surface-volume configuration. In some embodiments, the transmit coils are oriented to generate an RF magnetic field in directions substantially orthogonal to a static gradient field, and the receive coils are oriented to sense RF EPR signal in directions substantially orthogonal to the transmitted field and to the static field, to minimize coupling of the transmitted signal to the receive coils.

The present invention provides an apparatus and a corresponding method useful for electron paramagnetic resonance imaging, in situ and in vivo, using high-isolation transmit/receive (TX/RX) coils, which, in some embodiments, provide microenvironmental images that are representative of particular internal structures in the human body and spatially resolved images of tissue/cell protein signals responding to conditions (such as hypoxia) that show the temporal sequence of certain biological processes, and, in some embodiments, that distinguish malignant tissue from healthy tissue. In some embodiments, the TX/RX coils are in a surface, volume or surface-volume configuration. In some embodiments, the transmit coils are oriented to generate an RF magnetic field in directions substantially orthogonal to a static gradient field, and the receive coils are oriented to sense RF EPR signal in directions substantially orthogonal to the transmitted field and to the static field, to minimize coupling of the transmitted signal to the receive coils.