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

Review of Scientific Instruments

Active position stabilization of an atomic cloud in a narrow-line magneto-optical trap using a Raspberry Pi

Christian Sillus, Tobias Franzen, Bastian Pollklesener, Axel Görlitz

Published Mar 1, 2021• 3 citations
Publisher

Abstract

We report on a simple method for an active position stabilization of an atomic cloud trapped in a magneto-optical trap operating on the narrow 182 kHz intercombination line of atomic ytterbium. Our method makes use of the significant sensitivity of the position of a narrow-line magneto-optical trap (MOT) on the laser frequency. After in situ detection of the MOT position using a Pi Camera, an error signal is generated by a Raspberry Pi, which is directly fed back onto the laser frequency. Thus, perturbations of the MOT position, e.g., due to drifts of the Zerodur cavity to which the MOT laser is stabilized or the ambient magnetic field, can be compensated directly. Our method allows for long-term stabilization of the MOT position on a 10 µm scale and thus improves loading of a tightly focused optical trap.

DOI
10.1063/5.0040257

Related papers

Continuous cloud position spectroscopy using a magneto-optical trap

Benedikt Heizenreder, Ananya Sitaram, Sana Boughdachi +4 more

We demonstrate a continuous spectroscopy technique with frequency sensitivity well below the natural transition linewidth, while maintaining a locking range hundreds of times larger. The method exploits the position dependence of a continuous, broadband magneto-optical trap (MOT) operating on the 7.5-kHz-wide intercombination line of strontium. We show that the frequency sensitivity is fundamentally insensitive to the effective MOT laser linewidth. By applying active feedback on the MOT position to a dispersion-optimized frequency comb, which serves as the reference for stabilizing the MOT laser (Boughdachi , arXiv:2507.23617), we achieve a frequency instability below 4.4 × 10 − 13 after 400 s of averaging in both the optical and radio-frequency domains, surpassing the performance of conventional hot-vapor modulation transfer spectroscopy. Our method is a broadly applicable alternative route to frequency references in the high 10 − 14 range around 100 s.

arXiv:2509.07736•Physical Review Applied•Feb 18, 2026•0 citations

Crossed-beam slowing to enhance narrow-line ytterbium magneto-optic traps

Benjamin Plotkin-Swing, Anna Wirth-Singh, Daniel Gochnauer +3 more

We demonstrate a method to enhance the atom loading rate of a ytterbium (Yb) magneto-optic trap (MOT) operating on the 556 nm 1S0 → 3P1 intercombination transition (narrow linewidth Γg = 2π × 182 kHz). Following traditional Zeeman slowing of an atomic beam near the 399 nm 1S0 → 1P1 transition (broad linewidth Γp = 2π × 29 MHz), two laser beams in a crossed-beam geometry, frequency tuned near the same transition, provide additional slowing immediately prior to the MOT. Using this technique, we observe an improvement by a factor of 6 in the atom loading rate of a narrow-line Yb MOT. The relative simplicity and generality of this approach make it readily adoptable to other experiments involving narrow-line MOTs. We also present a numerical simulation of this two-stage slowing process, which shows good agreement with the observed dependence on experimental parameters, and use it to assess potential improvements to the method.

arXiv:2004.10298•Review of Scientific Instruments•Sep 1, 2020•17 citations

Direct loading of a large Yb MOT on the 1 S 0 → 3 P 1 transition

Alexander Guttridge, S. A. Hopkins, S. L. Kemp +6 more

Abstract We report a robust technique for laser frequency stabilisation that enables the reproducible loading of in excess of 10 9 Yb atoms from a Zeeman slower directly into a magneto-optical trap (MOT) operating on the 1 S 0 → 3 P 1 transition, without the need for a first stage MOT on the 1 S 0 → 1 P 1 transition. We use a simple atomic beam apparatus to generate narrow fluorescence signals on both the 399 nm 1 S 0 → 1 P 1 transition used for the Zeeman slower and the 556 nm 1 S 0 → 3 P 1 transition. We present in detail the methods for obtaining spectra with a high signal-to-noise ratio and demonstrate error signals suitable for robust frequency stabilisation. Finally we demonstrate the stability and precision of our technique through sensitive measurements of the gravitational sag of the Yb MOT as a function of the intensity of the laser cooling beams, which are in good agreement with theory. These results will be important for efficient loading of the atoms into an optical dipole trap.

arXiv:1512.06723•Journal of Physics B Atomic Molecular and Optical Physics•Jun 28, 2016•32 citations

Realization of Green MOT for Ytterbium Atoms

Zhao Peng-Yii, Xiong Zhuan-Xian, Yun Long +2 more

We report the experimental realization of a magneto-optical trap (MOT) of 174 Yb atoms operating on the 1 So− 3 P 1 intercombination transition at 555.8 nm. The green MOT is loaded by a Zeeman-slowed atomic beam. In order to increase the capture velocity of the MOT, we use the trapping laser beams consisting of five discrete frequency components obtained by modulating the laser light through an electro-optic modulator. The trapped atomic number of the 174 Yb isotope is about 6.2 × 10 5 , and the temperature of the cold atomic cloud is estimated to be about 100 μK. The success of the green MOT is an important step towards the goal of an ytterbium optical clock.

Chinese Physics Letters•Aug 1, 2009•12 citations

Two-color magneto-optical trap with small magnetic field for ytterbium

Akio Kawasaki, Boris Braverman, QinQin Yu +1 more

Abstract We report a two-color magneto-optical trap (MOT) for ytterbium atoms where the slowing and trapping functions are separately performed by the singlet transition light ( ) and the triplet transition light ( ), respectively. The two-color MOT is achieved by simultaneously applying laser light on both the broad-linewidth singlet transition and the narrow-linewidth triplet transition. It is highly robust against laser power imbalance even at very low magnetic field gradients, and can operate at magnetic field gradients down to 2 G cm −1 where a conventional MOT using the singlet transition is unable to trap atoms. We load and trap up to atoms directly from an atomic beam at 700 K.

arXiv:1502.07240•Journal of Physics B Atomic Molecular and Optical Physics•Jun 26, 2015•22 citations

Fiber-comb-stabilized light source at 556 nm for magneto-optical trapping of ytterbium

Masami Yasuda, Takuya Kohno, Hajime Inaba +4 more

A frequency-stabilized light source emitting at 556 nm is realized by frequency doubling a 1112 nm laser, which is phase locked to a fiber-based optical frequency comb. The 1112 nm laser is either an ytterbium (Yb)-doped distributed feedback fiber laser or a master-slave laser system that uses an external cavity diode laser as a master laser. We have achieved the continuous frequency stabilization of the light source over a 5 day period. With the light source, we have completed the second-stage magneto-optical trapping (MOT) of Yb atoms using the S10–P31 intercombination transition. The temperature of the ultracold atoms in the MOT was 40 μK when measured using the time-of-flight method, and this is sufficient for loading the atoms into an optical lattice. The fiber-based frequency comb is shown to be a useful tool for controlling the laser frequency in cold-atom experiments.

arXiv:1005.3152•Journal of the Optical Society of America B•Jun 15, 2010•24 citations
We report on a simple method for an active position stabilization of an atomic cloud trapped in a magneto-optical trap operating on the narrow 182 kHz intercombination line of atomic ytterbium. Our method makes use of the significant sensitivity of the position of a narrow-line magneto-optical trap (MOT) on the laser frequency. After in situ detection of the MOT position using a Pi Camera, an error signal is generated by a Raspberry Pi, which is directly fed back onto the laser frequency. Thus, perturbations of the MOT position, e.g., due to drifts of the Zerodur cavity to which the MOT laser is stabilized or the ambient magnetic field, can be compensated directly. Our method allows for long-term stabilization of the MOT position on a 10 µm scale and thus improves loading of a tightly focused optical trap.
We demonstrate a continuous spectroscopy technique with frequency sensitivity well below the natural transition linewidth, while maintaining a locking range hundreds of times larger. The method exploits the position dependence of a continuous, broadband magneto-optical trap (MOT) operating on the 7.5-kHz-wide intercombination line of strontium. We show that the frequency sensitivity is fundamentally insensitive to the effective MOT laser linewidth. By applying active feedback on the MOT position to a dispersion-optimized frequency comb, which serves as the reference for stabilizing the MOT laser (Boughdachi , arXiv:2507.23617), we achieve a frequency instability below 4.4 × 10 − 13 after 400 s of averaging in both the optical and radio-frequency domains, surpassing the performance of conventional hot-vapor modulation transfer spectroscopy. Our method is a broadly applicable alternative route to frequency references in the high 10 − 14 range around 100 s.
We demonstrate a method to enhance the atom loading rate of a ytterbium (Yb) magneto-optic trap (MOT) operating on the 556 nm 1S0 → 3P1 intercombination transition (narrow linewidth Γg = 2π × 182 kHz). Following traditional Zeeman slowing of an atomic beam near the 399 nm 1S0 → 1P1 transition (broad linewidth Γp = 2π × 29 MHz), two laser beams in a crossed-beam geometry, frequency tuned near the same transition, provide additional slowing immediately prior to the MOT. Using this technique, we observe an improvement by a factor of 6 in the atom loading rate of a narrow-line Yb MOT. The relative simplicity and generality of this approach make it readily adoptable to other experiments involving narrow-line MOTs. We also present a numerical simulation of this two-stage slowing process, which shows good agreement with the observed dependence on experimental parameters, and use it to assess potential improvements to the method.
Abstract We report a robust technique for laser frequency stabilisation that enables the reproducible loading of in excess of 10 9 Yb atoms from a Zeeman slower directly into a magneto-optical trap (MOT) operating on the 1 S 0 → 3 P 1 transition, without the need for a first stage MOT on the 1 S 0 → 1 P 1 transition. We use a simple atomic beam apparatus to generate narrow fluorescence signals on both the 399 nm 1 S 0 → 1 P 1 transition used for the Zeeman slower and the 556 nm 1 S 0 → 3 P 1 transition. We present in detail the methods for obtaining spectra with a high signal-to-noise ratio and demonstrate error signals suitable for robust frequency stabilisation. Finally we demonstrate the stability and precision of our technique through sensitive measurements of the gravitational sag of the Yb MOT as a function of the intensity of the laser cooling beams, which are in good agreement with theory. These results will be important for efficient loading of the atoms into an optical dipole trap.
We report the experimental realization of a magneto-optical trap (MOT) of 174 Yb atoms operating on the 1 So− 3 P 1 intercombination transition at 555.8 nm. The green MOT is loaded by a Zeeman-slowed atomic beam. In order to increase the capture velocity of the MOT, we use the trapping laser beams consisting of five discrete frequency components obtained by modulating the laser light through an electro-optic modulator. The trapped atomic number of the 174 Yb isotope is about 6.2 × 10 5 , and the temperature of the cold atomic cloud is estimated to be about 100 μK. The success of the green MOT is an important step towards the goal of an ytterbium optical clock.
Abstract We report a two-color magneto-optical trap (MOT) for ytterbium atoms where the slowing and trapping functions are separately performed by the singlet transition light ( ) and the triplet transition light ( ), respectively. The two-color MOT is achieved by simultaneously applying laser light on both the broad-linewidth singlet transition and the narrow-linewidth triplet transition. It is highly robust against laser power imbalance even at very low magnetic field gradients, and can operate at magnetic field gradients down to 2 G cm −1 where a conventional MOT using the singlet transition is unable to trap atoms. We load and trap up to atoms directly from an atomic beam at 700 K.
A frequency-stabilized light source emitting at 556 nm is realized by frequency doubling a 1112 nm laser, which is phase locked to a fiber-based optical frequency comb. The 1112 nm laser is either an ytterbium (Yb)-doped distributed feedback fiber laser or a master-slave laser system that uses an external cavity diode laser as a master laser. We have achieved the continuous frequency stabilization of the light source over a 5 day period. With the light source, we have completed the second-stage magneto-optical trapping (MOT) of Yb atoms using the S10–P31 intercombination transition. The temperature of the ultracold atoms in the MOT was 40 μK when measured using the time-of-flight method, and this is sufficient for loading the atoms into an optical lattice. The fiber-based frequency comb is shown to be a useful tool for controlling the laser frequency in cold-atom experiments.