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We show that a low finesse cavity can be efficient for detecting neutral atoms. The low finesse can be compensated for by decreasing the mode waist of the cavity. We have used a near concentric resonator with a beam waist of 12$\mu$m and a…

Atomic Physics · Physics 2009-11-11 Albrecht Haase , Björn Hessmo , Jörg Schmiedmayer

Progress in electromagnetic induction imaging with atomic magnetometers has brought its domain to the edge of the regime useful for biomedical imaging. However, a demonstration of imaging below the required 1 Sm$^{-1}$ level is still…

Instrumentation and Detectors · Physics 2020-04-02 Cameron Deans , Luca Marmugi , Ferruccio Renzoni

Stand-off magnetometry allows measuring magnetic field at a distance, and can be employed in geophysical research, hazardous environment monitoring, and security applications. Stand-off magnetometry based on resonant scattering from atoms…

Magnetic resonance of sodium fluorescence is studied with varying laser intensity, duty cycle, and field strength. A magnetometer based on sodium vapor cell filled with He buffer gas is demonstrated, which uses a single amplitude-modulated…

Optics · Physics 2018-02-14 Tingwei Fan , Lei Zhang , Xuezong Yang , Shuzhen Cui , Tianhua Zhou , Yan Feng

We report on a compact, tunable, and scalable to large arrays imaging device, based on a radio-frequency optically pumped atomic magnetometer operating in magnetic induction tomography modality. Imaging of conductive objects is performed at…

Atomic Physics · Physics 2016-03-11 Cameron Deans , Luca Marmugi , Sarah Hussain , Ferruccio Renzoni

Magnetic field imaging is a valuable resource for signal source localization and characterization. This work reports an optically pumped magnetometer (OPM) based on the free-induction-decay (FID) protocol, that implements microfabricated…

Atomic force microscopy using a magnetic tip is a promising tool for investigating conductivity on the nano-scale. By the oscillating magnetic tip eddy currents are induced in the conducting parts of the sample which can be detected in the…

Atomic Physics · Physics 2009-11-13 Tino Roll , Marion Meier , Ulrich Fischer , Marika Schleberger

Magnetometry with nitrogen-vacancy (NV) centers has so far been measured via emission of light from NV centers or via absorption at the singlet transition at 1042 nm. Here, we demonstrate a phenomenon of broadband optical absorption by the…

In 1968, F.L. Shapiro published the suggestion that one could search for an electron EDM by applying a strong electric field to a substance that has an unpaired electron spin; at low temperature, the EDM interaction would lead to a net…

Nuclear Experiment · Physics 2008-11-26 S. K. Lamoreaux

We consider using optomechanical accelerometers as resonant detectors for ultralight dark matter. As a concrete example, we describe a detector based on a silicon nitride membrane fixed to a beryllium mirror, forming an optical cavity. The…

Quantum Physics · Physics 2021-02-17 Jack Manley , Mitul Dey Chowdhury , Daniel Grin , Swati Singh , Dalziel J. Wilson

We present a novel approach allowing an optically pumped magnetometer (OPM) to be operated within Earth's magnetic field as a vector magnetometer whose sensitive axis can be freely defined. This approach enables the measurement of any…

Instrumentation and Detectors · Physics 2024-08-20 Thomas Schönau , Theo Scholtes , Florian Wittkämper , Alexander Sekels , Stefan Hiebel , Gregor Oelsner , Ronny Stolz

Cascades from high-energy particles produce a brief current and associated magnetic fields. Even sub-nanosecond duration magnetic fields can be detected with a relatively low bandwidth system by latching image currents on a capacitor. At…

Instrumentation and Detectors · Physics 2015-05-26 David Saltzberg , Peihao Sun

We demonstrate a sensitive optically-pumped magnetometer using rubidium vapor and 0.75 amg of nitrogen buffer gas in a sub-mm-width sensing channel excavated by femtosecond laser writing followed by chemical etching. The channel is buried…

A method to measure the electrical resistivity of materials using magnetic-force microscopy (MFM) is discussed, where MFM detects the magnetic field caused by the tip-oscillation-induced eddy current. To achieve high sensitivity, a high…

Materials Science · Physics 2025-04-10 Kazuma Okamoto , Takumi Imura , Satoshi Abo , Fujio Wakaya , Katsuhisa Murakami , Masayoshi Nagao

We have demonstrated a remote magnetometer based on sodium atoms in the Earth's mesosphere, at a 106-kilometer distance from our instrument. A 1.33-watt laser illuminated the atoms, and the magnetic field was inferred from back-scattered…

Instrumentation and Methods for Astrophysics · Physics 2017-02-17 Thomas J. Kane , Paul D. Hillman , Craig A. Denman , Michael Hart , R. Phillip Scott , Michael E. Purucker , Stephen J. Potashnik

Convolutional Neural Networks (CNNs) are nowadays often employed in vision-based perception stacks for safetycritical applications such as autonomous driving or Unmanned Aerial Vehicles (UAVs). Due to the safety requirements in those use…

Computer Vision and Pattern Recognition · Computer Science 2022-09-02 Yannik Blei , Nicolas Jourdan , Nils Gählert

Realistic applications in metal detection involve multiple inhomogeneous conducting permeable objects and the aim of this paper is to characterise such objects by polarizability tensors. We show that, for the eddy current model, the leading…

Analysis of PDEs · Mathematics 2018-09-25 P. D. Ledger , W. R. B. Lionheart , A. A. S. Amad

A novel setup for the measurement of magnetic fields external to certain antiferromagnets and generally weakly remanent magnetic materials is presented. The setup features a highly sensitive Super Conducting Quantum Interference Device…

The lower critical magnetic field, $H_{c1}$, of superconductors is measured by using ensembles of NV-centers-in-diamond optical magnetometry. The technique is minimally invasive, and has sub-gauss field sensitivity and sub-$\mu$m spatial…

Superconductivity · Physics 2019-01-23 K. R. Joshi , N. M. Nusran , K. Cho , M. A. Tanatar , W. R. Meier , S. L. Bud'ko , P. C. Canfield , R. Prozorov

A sequential detection and tracking (SDT) approach is proposed for detection and tracking of very low signal-to-noise (SNR) objects. The proposed approach is compared with two existing particle filter track-before-track (TBD) methods. It is…

Systems and Control · Electrical Eng. & Systems 2023-12-27 Reza Rezaie