91 research outputs found
Magnetic induction tomography using an all-optical Rb atomic magnetometer
We demonstrate Magnetic Induction Tomography (MIT) with an all-optical atomic
magnetometer. Our instrument creates a conductivity map of conductive objects.
Both shape and size of the imaged samples compare very well with the actual
shape and size. Given the potential of all-optical atomic magnetometers for
miniaturization and extreme sensitivity, the proof-of-principle presented here
opens up promising avenues in the development of instrumentation for magnetic
induction tomography.Comment: 4 pages, 3 figures. Minor modifications, typos amended, references to
f_ac and f_dc inserted in Fig.
Light shift averaging in paraffin-coated alkali vapor cells
Light shifts are an important source of noise and systematics in optically
pumped magnetometers. We demonstrate that the long spin coherence time in
paraffin-coated cells leads to spatial averaging of the light shifts over the
entire cell volume. This renders the averaged light shift independent, under
certain approximations, of the light-intensity distribution within the sensor
cell. These results and the underlying mechanism can be extended to other
spatially varying phenomena in anti-relaxation-coated cells with long coherence
times.Comment: 6 pages, 4 figure
Microwave-free magnetometry with nitrogen-vacancy centers in diamond
We use magnetic-field-dependent features in the photoluminescence of
negatively charged nitrogen-vacancy centers to measure magnetic fields without
the use of microwaves. In particular, we present a magnetometer based on the
level anti-crossing in the triplet ground state at 102.4 mT with a demonstrated
noise floor of 6 nT/, limited by the intensity noise of the
laser and the performance of the background-field power supply. The technique
presented here can be useful in applications where the sensor is placed closed
to conductive materials, e.g. magnetic induction tomography or magnetic field
mapping, and in remote-sensing applications since principally no electrical
access is needed.Comment: 5 pages, 4 figure
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