RESUMEN
We present a design to increase the amount of collected fluorescence emitted by nitrogen-vacancy color centers in diamond used for quantum-sensing. An improvement was measured in collected fluorescence when comparing oppositely faced emitting surfaces by a factor of 3.8(1). This matches ray-tracing simulation results. This design therefore improves on the shot noise limited sensitivity in optical readout-based measurements of, for instance, magnetic and electric fields, pressure, temperature, and rotations.
RESUMEN
We propose a hybrid laser system consisting of a semiconductor external cavity laser associated to an intra-cavity diamond etalon doped with nitrogen-vacancy color centers. We consider laser emission tuned to the infrared absorption line that is enhanced under the magnetic field dependent nitrogen-vacancy electron spin resonance and show that this architecture leads to a compact solid-state magnetometer that can be operated at room-temperature. The sensitivity to the magnetic field limited by the photonshot-noise of the output laser beam is estimated to be less than 1 pT/Hz. Unlike usual NV center infrared magnetometry, this method would not require an external frequency stabilized laser. Since the proposed system relies on the competition between the laser threshold and an intracavity absorption, such laser-based optical sensor could be easily adapted to a broad variety of sensing applications based on absorption spectroscopy.
RESUMEN
Halbach magnets are a source of homogeneous magnetic field in an enclosed volume while keeping stray fields at a minimum. Here, we present the design, construction, and characterization for a stack of two Halbach rings with 10 cm inner diameter providing a homogeneous (<100 ppm over 1.0×1.0×0.5cm3) magnetic field of around 105 mT, which will be used for a diamond based microwave-free widefield imaging setup. The final characterization is performed with a novel fiberized diamond-based sensor on a 3D translation stage documenting the high homogeneity of the constructed Halbach array and its suitability for the proposed use.