A process of assigning a colour grade to a diamond, including the steps of (i) determining the N3 and C-center content of a diamond (110); (ii) comparing the N3 and C-center content of the diamond with a previously acquired data set from a plurality of diamonds each having a colour grading previously assigned thereto, and (iii) assigning a colour grade to the diamond upon a correlation of the N3 and C-center content of said diamond with a grade of said previously acquired data set; wherein said previously acquired data set comprises a correlation between N3 and C center content and optical absorbance in the visible light spectrum for each diamond of said plurality of diamonds.

An electron paramagnetic resonance (EPR) apparatus has a main magnet with two pole pieces on either side of an air gap, and at least one EPR probe head adapted for rapid scan (RS) measurements positioned between the pole pieces of a main magnet, and a pair of RS coils. The EPR apparatus further has at least one EPR probe head adapted for continuous wave (CW) signal measurements, positioned between the pole pieces of the main magnet, and a carrier which allows insertion of the RS coils into the air gap between the pole pieces in an operation position and extraction of the RS coils from the air gap to a storage position outside of a CW operating volume. The system allows a quick and secure change of the RS coils, safely and rapidly, by a single user.

An electron paramagnetic resonance (EPR) apparatus has a main magnet with two pole pieces on either side of an air gap, and at least one EPR probe head adapted for rapid scan (RS) measurements positioned between the pole pieces of a main magnet, and a pair of RS coils. The EPR apparatus further has at least one EPR probe head adapted for continuous wave (CW) signal measurements, positioned between the pole pieces of the main magnet, and a carrier which allows insertion of the RS coils into the air gap between the pole pieces in an operation position and extraction of the RS coils from the air gap to a storage position outside of a CW operating volume. The system allows a quick and secure change of the RS coils, safely and rapidly, by a single user.

A diamond magnetic sensor including diamond containing at least one NV.sup.− center, a microwave generator which emits microwaves to the diamond, an excitation light generator which emits excitation light to the NV.sup.− center of the diamond, and a fluorescence sensor which receives fluorescence produced from the NV.sup.− center of the diamond includes a pattern measurement apparatus which measures a temporal change pattern of magnetic field intensity based on variation in fluorescence intensity sensed by the fluorescence sensor.

The following relates generally to a magnetic imaging sensor configured to capture vector magnetometry data. One disclosed aspect involves: using a green pumping laser to excite nitrogen vacancy (NV) centers of a diamond crystal; and, through a filter stacked between the diamond crystal and a pixilated image sensor, passing red light caused by the excitation to the pixilated image sensor.

A measurement device includes a microwave generator, an electron spin resonance member, and an observation system. The microwave generator is configured to generate a microwave. The microwave is configured for an electron spin quantum operation based on a Rabi oscillation. The microwave generator has a coil configured to emit the microwave and an electrostatic capacitance member electrically connected in parallel to the coil. The microwave is irradiated to the electron spin resonance member. The observation system is configured to measure a physical quantity in a measured field in response to a state of the electron spin resonance member when the electron spin resonance member is irradiated by the microwave. The electrostatic capacitance member is directly connected to the coil or is arranged between the coil and an electric element that is electrically connected to the coil.

Improved loop-gap resonators applicable to Electron-Spin Resonance spectroscopy and to quantum computing employ interdigitated capacitor structures to dramatically increase the capacitance of the resonator, along with corresponding decreases in loop size to enable measurements of small-volume samples or individual quantum bits (qubits). The interdigitated-capacitor structures are designed to minimize parasitic inductance.

Improved loop-gap resonators applicable to Electron-Spin Resonance spectroscopy and to quantum computing employ interdigitated capacitor structures to dramatically increase the capacitance of the resonator, along with corresponding decreases in loop size to enable measurements of small-volume samples or individual quantum bits (qubits). The interdigitated-capacitor structures are designed to minimize parasitic inductance.

A magnetometer includes a sample signal device; a reference signal device; a microwave field generator operable to apply a microwave field to the sample signal device and the reference signal device; an optical source configured to emit light including light of a first wavelength that interacts optically with the sample signal device and with the reference signal device; at least one photodetector arranged to detect a sample photoluminescence signal including light of a second wavelength emitted from the sample signal device and a reference photoluminescence signal including light of the second wavelength emitted from the reference signal device, in which the first wavelength is different from the second wavelength; and a magnet arranged adjacent to the sample signal device and the reference signal device.

A measurement device includes a microwave generator, an electron spin resonance member, and an observation system. The microwave generator is configured to generate a microwave. The microwave is configured for an electron spin quantum operation based on a Rabi oscillation. The microwave generator has a coil configured to emit the microwave and an electrostatic capacitor electrically connected in parallel to the coil. The microwave is irradiated to the electron spin resonance member. The observation system is configured to measure a physical quantity in a measured field in response to a state of the electron spin resonance member when the electron spin resonance member is irradiated by the microwave. The coil has first and second ends from which first and second legs continuously extended. The electrostatic capacitor spans the first and second legs and is electrically connected in parallel to the coil.