Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0805.3797 · Physical Review A

Faraday spectroscopy of atoms confined in a dark optical trap

Matthew L. Terraciano, Mark Bashkansky, Fredrik K. Fatemi

Published Jun 18, 2008• 25 citations
arXivHTMLPDF

Abstract

We demonstrate Faraday spectroscopy with a high duty cycle and sampling rate using atoms confined to a blue-detuned optical trap. Our trap consists of a crossed pair of high-charge-number hollow laser beams, which forms a dark, boxlike potential. We have used this to measure transient magnetic fields in a $500\text{\ensuremath{-}}\ensuremath{\mu}\text{m}$-diameter spot over a 400 ms time window with nearly unit duty cycle at a 500-Hz sampling rate. We use these measurements to quantify and compensate time-varying magnetic fields to $\ensuremath{\approx}10\text{ }$ nT per time sample.

DOI
10.1103/physreva.77.063417

Related papers

Magnetometry with High Sampling Rate using Cold Atoms in a Movable Dark Optical Trap

Matthew L. Terraciano, Mark Bashkansky, Fredrik K. Fatemi

We use Faraday spectroscopy of atoms confined to a crossed hollow beam trap to measure the magnetic field in a 200-micron-diameter spot with kilohertz sampling rate. Magnetic field maps are acquired by dynamic trap scanning.

Frontiers in Optics•Jan 1, 2008•0 citations

Spatially resolved magnetometry using cold atoms in dark optical tweezers

Fredrik K. Fatemi, Mark Bashkansky

We use Faraday spectroscopy of atoms confined to crossed hollow beam tweezers to map magnetic fields over 3 millimeters with 200 micron resolution in a single trap loading cycle. The hollow beams are formed using spatial light modulation, and the trap location is scanned using acousto-optic deflectors. We demonstrate the technique by mapping a linear quadrupole magnetic field with 10 nT sensitivity.

Optics Express•Jan 19, 2010•13 citations

Spatial and Temporal Magnetometry Using Cold Atoms in Dark Optical Tweezers

Fredrik K. Fatemi, Matthew L. Terraciano, Mark Bashkansky

We use Faraday spectroscopy of atoms confined to crossed hollow beam tweezers to map magnetic fields over several millimeters with 100 micron resolution. The traps permit several hundred measurements in a single loading cycle.

Conference on Lasers and Electro-Optics•Jan 1, 2009•0 citations

A single hollow-beam optical trap for cold atoms

S. A. Kulin, S. Aubin, Steven Christe +3 more

We present an optical trap for atoms which we have developed for precision spectroscopy measurements. Cold atoms are captured in a dark region of space inside a blue-detuned hollow laser beam formed by an axicon. We analyse the light potential in a ray optics picture and experimentally demonstrate trapping of laser-cooled metastable xenon atoms.

arXiv:physics/0107011•Journal of Optics B Quantum and Semiclassical Optics•Oct 15, 2001•53 citations

Tightly confined atoms in optical dipole traps

Matthias C. Schulz

This thesis reports on the design, setup, and operation of a new atom trap apparatus, which is developed to confine few rubidium atoms in ultrahigh vacuum by means of taylored and dynamically variable light potentials (dipole traps), thus making the atoms available for spectroscopy and controlled manipulations. To maintain low background pressure, atoms of a vapour cell are transferred into a cold atomic beam by laser cooling techniques, and accumulated by a magneto-optic trap (MOT) in a separate part of the vacuum system. The laser cooled atoms are then transferred into dipole traps made of focused far-off-resonant laser fields in single or crossed-beam geometry, which are superimposed with the center of the MOT. Gaussian as well as hollow Laguerre-Gaussian (LG01) beam profiles are used with red-detuned and blue-detuned light. Microfabricated dielectric phase objects allow the efficient and robust mode conversion of Gaussian into Laguerre-Gaussian laser beams. Trap geometries can easily be changed due to the highly flexible experimental setup. The dipole trap laser beams have powers up to several hundred milliwatts and are focused to around 10 m. At a detuning of several tens of nanometers from the atomic resonance, the resulting traps are a few millikelvin deep, and the trapped atoms exhibit motional frequencies near 30 kHz, trap light scattering rates of a few hundred photons per second per atom, and storage times of several seconds. The number of dipole-trapped atoms ranges from more than ten thousand to below ten. The dipole-trapped atoms are detected either by a photon counting system with efficient straylight discrimination, or by recapture into the MOT, which is imaged onto a sensitive photodiode and a CCD-camera. Due to the strong AC-Stark shift imposed by the high-intensity trapping light, energy-selective resonant excitation and detection of the stored atoms is possible. The measured energy distribution is consistent with a harmonic potential shape and allows for the determination of temperatures and heating rates. From initial measurements, the thermal energy is found to be about 10 % of the trap depth. Using a crossed-beam geometry with red-detuned laser light, efficient transfer of atoms between the beams is observed. Optimum transfer occurs when the two beams cross at a radial offset, which can qualitatively be understood when the particle energy and geometrical properties of the two-beam trapping potential are considered. Numerical simulations reproduce the general features of the measured transfer efficiency vs. radial beam offset. This experiment is a first step towards dynamically variable potentials. Atoms have been radially confined in a blue-detuned hollow beam, and their decay time has been determined. This configuration is currently extended to a three-dimensionally confining blue-detuned dipole trap. For advanced laser cooling, state manipulation and spectroscopy of trapped atoms, a system of two diode lasers has been set up which are phase-coherently locked with a difference frequency near 6.834 GHz, to drive Raman transitions between the hyperfine-split ground states of 87Rb atoms. Resonances of such a transition have been recorded in a buffer gas loaded rubidium vapour cell with linewidths below 100 Hz.

•Jan 1, 2002•7 citations

Sensitive spectroscopy and atom dynamics in a single beam optical trap

Nir Friedman, Lev Khaykovich, Stanislav B. Baluschev +4 more

Summary form only given. Cold atoms are trapped in a dark optical trap which is created by a rapidly (up to 400 kHz) scanning far-detuned laser beam, where the scanning speed is much faster then any characteristic atomic motional time scale. This concept offers the possibility to form nearly arbitrary-shaped effective optical potentials and also to change them in real time. We report on spectroscopic and dynamical measurements in such a rotating beam trap.

Conference on Lasers and Electro-Optics•Aug 29, 2005•0 citations
We demonstrate Faraday spectroscopy with a high duty cycle and sampling rate using atoms confined to a blue-detuned optical trap. Our trap consists of a crossed pair of high-charge-number hollow laser beams, which forms a dark, boxlike potential. We have used this to measure transient magnetic fields in a 500\ensuremath-\ensuremathμm500\text{\ensuremath{-}}\ensuremath{\mu}\text{m}500\ensuremath-\ensuremathμm-diameter spot over a 400 ms time window with nearly unit duty cycle at a 500-Hz sampling rate. We use these measurements to quantify and compensate time-varying magnetic fields to \ensuremath≈10 \ensuremath{\approx}10\text{ }\ensuremath≈10  nT per time sample.
This thesis reports on the design, setup, and operation of a new atom trap apparatus, which is developed to confine few rubidium atoms in ultrahigh vacuum by means of taylored and dynamically variable light potentials (dipole traps), thus making the atoms available for spectroscopy and controlled manipulations. To maintain low background pressure, atoms of a vapour cell are transferred into a cold atomic beam by laser cooling techniques, and accumulated by a magneto-optic trap (MOT) in a separate part of the vacuum system. The laser cooled atoms are then transferred into dipole traps made of focused far-off-resonant laser fields in single or crossed-beam geometry, which are superimposed with the center of the MOT. Gaussian as well as hollow Laguerre-Gaussian (LG01) beam profiles are used with red-detuned and blue-detuned light. Microfabricated dielectric phase objects allow the efficient and robust mode conversion of Gaussian into Laguerre-Gaussian laser beams. Trap geometries can easily be changed due to the highly flexible experimental setup. The dipole trap laser beams have powers up to several hundred milliwatts and are focused to around 10 m. At a detuning of several tens of nanometers from the atomic resonance, the resulting traps are a few millikelvin deep, and the trapped atoms exhibit motional frequencies near 30 kHz, trap light scattering rates of a few hundred photons per second per atom, and storage times of several seconds. The number of dipole-trapped atoms ranges from more than ten thousand to below ten. The dipole-trapped atoms are detected either by a photon counting system with efficient straylight discrimination, or by recapture into the MOT, which is imaged onto a sensitive photodiode and a CCD-camera. Due to the strong AC-Stark shift imposed by the high-intensity trapping light, energy-selective resonant excitation and detection of the stored atoms is possible. The measured energy distribution is consistent with a harmonic potential shape and allows for the determination of temperatures and heating rates. From initial measurements, the thermal energy is found to be about 10 % of the trap depth. Using a crossed-beam geometry with red-detuned laser light, efficient transfer of atoms between the beams is observed. Optimum transfer occurs when the two beams cross at a radial offset, which can qualitatively be understood when the particle energy and geometrical properties of the two-beam trapping potential are considered. Numerical simulations reproduce the general features of the measured transfer efficiency vs. radial beam offset. This experiment is a first step towards dynamically variable potentials. Atoms have been radially confined in a blue-detuned hollow beam, and their decay time has been determined. This configuration is currently extended to a three-dimensionally confining blue-detuned dipole trap. For advanced laser cooling, state manipulation and spectroscopy of trapped atoms, a system of two diode lasers has been set up which are phase-coherently locked with a difference frequency near 6.834 GHz, to drive Raman transitions between the hyperfine-split ground states of 87Rb atoms. Resonances of such a transition have been recorded in a buffer gas loaded rubidium vapour cell with linewidths below 100 Hz.