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

European Frequency and Time Forum

The progress of strontium optical clock at NIM

Shaokai Wang, Qiang Wang, Bai-Ke Lin, Ye Li, Yige Lin, Wang Min-Ming, Yang Zhao, Jian-Ping Cao, Erjun Zang, Tianchu Li, Zhanjun Fang

Published Apr 1, 2010• 0 citations
Publisher

Abstract

We report the experimental realization of88Sr magneto-optical trap (MOT) operating at the wavelength of 461 nm and 689nm. The blue MOT is loaded via a 32 cm long spin-flip type Zeeman slower which enhances the MOT population by a factor of 44. We have trapped 1.6×10888Sr atoms with the use of 679nm and 707nm repumping laser. The88Sr cloud has a temperature of about 2.3 mK, measured by recording the time evolution of the absorption signal. The 689nm laser used in our experiment has a line width of about 200Hz. To optimize the transfer efficiency, the laser spectrum is broadened by frequency modulation technique to about 2 MHz. The transfer efficiency from blue MOT to red MOT is about 20%.

DOI
10.1109/eftf.2010.6533714

Related papers

Cooling and Trapping 88 Sr Atoms with 461 nm Laser

Shaokai Wang, Wang Qiang, Lin Yi-Ge +5 more

We report the experimental realization of a 88Sr magneto-optical trap (MOT) operating at the wavelength of 461 nm. The MOT is loaded via a 32 cm long spin-flip type Zeeman slower which enhances the MOT population by a factor of 22. The total laser power available in our experiment is about 300 mW. We have trapped 1.6 × 108 88Sr atoms with a 679nm and 707 nm repumping laser. The two repumping lasers enhance the trap population and trap lifetime by factors of 11 and 7, respectively. The 88Sr cloud has a temperature of about 2.3 mK, measured by recording the time evolution of the absorption signal.

Chinese Physics Letters•Sep 1, 2009•23 citations

Efficient cooling and trapping of strontium atoms

Irène Ventrillard, Audrey Quessada, Richard P. Kovacich +4 more

We report the capture of cold strontium atoms in a magneto-optical trap (MOT) at a rate of 4 x 10(10) atoms/s. The MOT is loaded from an atomic beam decelerated by a Zeeman slower operating with a focused laser beam. The 461-nm laser, used for both cooling and trapping, was generated by sum-frequency mixing in a KTP crystal with diode lasers at 813 nm and a Nd:YAG laser at 1064 nm. As much as 115 mW of blue light was obtained.

Optics Letters•Mar 15, 2003•48 citations

Ultracold 88Sr atoms for an optical lattice clock

Thomas Legero, J. S. Raaj Vellore Winfred, F. Riehle +1 more

This paper reports results of cooling and trapping of88Sr for future use in an optical lattice clock. Strontium atoms are cooled to ultra-cold temperatures using a two-stage cooling process. In the first stage, atoms are captured from a Zeeman-slowed atomic beam and cooled to 2 mK in a magneto optical trap operated on the1So-1P1transition at 461 nm. The second cooling stage utilizes the spin forbidden1So-3P1transition at 689 nm. To reach ultra-cold temperatures, 50 ms of broadband cooling is followed by 28 ms long single frequency cooling. The transfer efficiency from the first to the second cooling stage was measured to be 23%, leaving 7 x 106 atoms at a temperature of 1 muK. The atomic cloud is overlapped with a horizontally oriented 1-D far-off resonance optical dipole trap (FORT) at 813 nm with an effective potential depth of 25 muK. Due to equal light shifts of the1Soand the3P1state simultaneous Doppler cooling during the atom loading into the FORT is possible which leads to a transfer efficiency into the dipole trap of up to 60%.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•May 1, 2007•4 citations

Towards a strontium based stationary optical lattice clock

Qasim Hassan Ubaid

Optical atomic clocks have proven to be the most stable clocks with the lowest systematic uncertainty which has now reached a record level of (9.4 X10/(^{19}/)). Thus optical clocks now surpass the best fountain Cs atomic clocks by three orders of magnitude which opens the prospect of using optical clocks as frequency standards for timekeeping in the near future. \n \nThis thesis describes the progress that has been made towards a stationary optical lattice clock based on strontium atoms, and reports the results of an ongoing characterization. \n \nAn experimental apparatus was designed and built to efficiently slow, cool, and trap the strontium atoms which represent the heart of the strontium optical lattice clock discussed in this thesis. The novel aspects of the experimental development described in the thesis comprise a frequency doubling cavity for producing 461 nm laser light employed for cooling and trapping the strontium atoms in the first stage cooling. This cavity provided sufficient power for cooling and trapping the strontium atoms for up to 300 mW of 461 nm laser light. Furthermore, a new design of Zeeman slower based on spherical permanent magnets was produced, built and characterized. \n \nThe slower is compact, tunable, easy to assemble and maintain, and cost-effective as the permanent magnets do not require any power supply or water cooling. It is suggested that this kind of Zeeman slower constitutes an ideal solution for portable optical clock systems. A blue magneto-optical trap was realized for the first time with such a Zeeman slower. With about 30 mW of a 461 nm laser, up to 6X10/(^8/) atoms were captured.

•Jul 20, 2020•0 citations

Magneto-Optical Trapping of Ytterbium Atoms with a 398.9 nm Laser

Zhao Peng-Yi, Xiong Zhuan-Xian, Jie Liang +2 more

We report the realization of ytterbium magneto-optical trap (MOT) operating on the dipole-allowed 1 S 0 — 1 P 1 transition at 398.9 nm. The MOT is loaded by a slowed atomic beam produced by a Zeeman slower. All seven stable isotopes of Yb atoms could be trapped separately at different laser detuning values. Over 10 7 174 Yb atoms are collected in the MOT, whereas the atom number of fermionic isotope 171 Yb is roughly 2.3 × 10 6 due to a lower abundance. Without the Zeeman slower, the trapped atom numbers are one order of magnitude lower. Both the even and odd isotopes are recognized as excellent candidates of optical clock transition, so the cooling and trapping of ytterbium atoms by the blue MOT is an important step for building an optical clock.

Chinese Physics Letters•Oct 1, 2008•16 citations

Narrow Line Cooling of 84Sr

Roger Ding

Laser cooling has become a powerful tool for producing quantum gases and has enabled the study of a wide range of phenomena only accessible at ultracold temperatures. This thesis will describe the implementation and characterization of a magneto-optical trap (MOT) for laser cooling strontium to microkelvin temperatures operating on the narrow 689nm transition (the “red” MOT). The red MOT is the second cooling stage required to create quantum degenerate gases of strontium, bridging the temperatures and densities produced by the first cooling stage (the 461 nm “blue” MOT) and the shallow conservative traps for evaporation to quantum degeneracy.

•Dec 12, 2016•0 citations
We report the experimental realization of88Sr magneto-optical trap (MOT) operating at the wavelength of 461 nm and 689nm. The blue MOT is loaded via a 32 cm long spin-flip type Zeeman slower which enhances the MOT population by a factor of 44. We have trapped 1.6×10888Sr atoms with the use of 679nm and 707nm repumping laser. The88Sr cloud has a temperature of about 2.3 mK, measured by recording the time evolution of the absorption signal. The 689nm laser used in our experiment has a line width of about 200Hz. To optimize the transfer efficiency, the laser spectrum is broadened by frequency modulation technique to about 2 MHz. The transfer efficiency from blue MOT to red MOT is about 20%.
We report the experimental realization of a 88Sr magneto-optical trap (MOT) operating at the wavelength of 461 nm. The MOT is loaded via a 32 cm long spin-flip type Zeeman slower which enhances the MOT population by a factor of 22. The total laser power available in our experiment is about 300 mW. We have trapped 1.6 × 108 88Sr atoms with a 679nm and 707 nm repumping laser. The two repumping lasers enhance the trap population and trap lifetime by factors of 11 and 7, respectively. The 88Sr cloud has a temperature of about 2.3 mK, measured by recording the time evolution of the absorption signal.
This paper reports results of cooling and trapping of88Sr for future use in an optical lattice clock. Strontium atoms are cooled to ultra-cold temperatures using a two-stage cooling process. In the first stage, atoms are captured from a Zeeman-slowed atomic beam and cooled to 2 mK in a magneto optical trap operated on the1So-1P1transition at 461 nm. The second cooling stage utilizes the spin forbidden1So-3P1transition at 689 nm. To reach ultra-cold temperatures, 50 ms of broadband cooling is followed by 28 ms long single frequency cooling. The transfer efficiency from the first to the second cooling stage was measured to be 23%, leaving 7 x 106 atoms at a temperature of 1 muK. The atomic cloud is overlapped with a horizontally oriented 1-D far-off resonance optical dipole trap (FORT) at 813 nm with an effective potential depth of 25 muK. Due to equal light shifts of the1Soand the3P1state simultaneous Doppler cooling during the atom loading into the FORT is possible which leads to a transfer efficiency into the dipole trap of up to 60%.
Optical atomic clocks have proven to be the most stable clocks with the lowest systematic uncertainty which has now reached a record level of (9.4 X10/(^{19}/)). Thus optical clocks now surpass the best fountain Cs atomic clocks by three orders of magnitude which opens the prospect of using optical clocks as frequency standards for timekeeping in the near future. \n \nThis thesis describes the progress that has been made towards a stationary optical lattice clock based on strontium atoms, and reports the results of an ongoing characterization. \n \nAn experimental apparatus was designed and built to efficiently slow, cool, and trap the strontium atoms which represent the heart of the strontium optical lattice clock discussed in this thesis. The novel aspects of the experimental development described in the thesis comprise a frequency doubling cavity for producing 461 nm laser light employed for cooling and trapping the strontium atoms in the first stage cooling. This cavity provided sufficient power for cooling and trapping the strontium atoms for up to 300 mW of 461 nm laser light. Furthermore, a new design of Zeeman slower based on spherical permanent magnets was produced, built and characterized. \n \nThe slower is compact, tunable, easy to assemble and maintain, and cost-effective as the permanent magnets do not require any power supply or water cooling. It is suggested that this kind of Zeeman slower constitutes an ideal solution for portable optical clock systems. A blue magneto-optical trap was realized for the first time with such a Zeeman slower. With about 30 mW of a 461 nm laser, up to 6X10/(^8/) atoms were captured.
We report the realization of ytterbium magneto-optical trap (MOT) operating on the dipole-allowed 1 S 0 — 1 P 1 transition at 398.9 nm. The MOT is loaded by a slowed atomic beam produced by a Zeeman slower. All seven stable isotopes of Yb atoms could be trapped separately at different laser detuning values. Over 10 7 174 Yb atoms are collected in the MOT, whereas the atom number of fermionic isotope 171 Yb is roughly 2.3 × 10 6 due to a lower abundance. Without the Zeeman slower, the trapped atom numbers are one order of magnitude lower. Both the even and odd isotopes are recognized as excellent candidates of optical clock transition, so the cooling and trapping of ytterbium atoms by the blue MOT is an important step for building an optical clock.
Laser cooling has become a powerful tool for producing quantum gases and has enabled the study of a wide range of phenomena only accessible at ultracold temperatures. This thesis will describe the implementation and characterization of a magneto-optical trap (MOT) for laser cooling strontium to microkelvin temperatures operating on the narrow 689nm transition (the “red” MOT). The red MOT is the second cooling stage required to create quantum degenerate gases of strontium, bridging the temperatures and densities produced by the first cooling stage (the 461 nm “blue” MOT) and the shallow conservative traps for evaporation to quantum degeneracy.