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

A compact laser system for a portable atom interferometry gravimeter

Qin Luo, Heng Zhang, Ke Zhang, Xiao‐Chun Duan, Zhong-Kun Hu, Lele Chen, Min-Kang Zhou

Published Apr 1, 2019• 43 citations
Publisher

Abstract

A compact laser system for a portable 87Rb atom interferometry gravimeter has been demonstrated in this work. This laser system is based on frequency doubling of a single seed laser at the wavelength of 1560 nm. The frequency of the seed laser is controlled by a digital unit with an analog feedback circuit. By using this frequency control method, the frequency of the laser system can be shifted over 1 GHz. Based on this method, the Raman frequency can be locked on the F = 3 → F′ = 4 transition of 85Rb atoms. Moreover, the Raman sideband and the repumping laser are generated by a phase modulator, and it can generate different laser frequencies to meet the requirements of a typical atom interferometer. Additional sidebands in the Raman beam produced from the phase modulator are optimized and reduced, allowing us to observe atom interference with a free evolution time of 320 ms. The control unit including the laser system has been integrated into a box with a volume of 1.5 m × 0.6 m × 0.6 m, and the weight of which is only 150 kg. Using this compact optical scheme, our atomic gravimeter has achieved a sensitivity of 53 μGal/Hz1/2 and a resolution of better than 1 μGal (1 μGal = 1 × 10−8 m/s2) in an integration time of 3000 s.

DOI
10.1063/1.5053132

Related papers

A SINGLE LASER OPERATED COLD ATOM GRAVIMETER

K. Bhardwaj, S. Singh, S. P. Ram +6 more

A cold atom gravimeter (CAG) using a single laser system has been developed. In the setup, the laser cooled Rb atoms are launched in the vertical upward direction and Doppler sensitive two-photon Raman pulse atom interferometry is applied to measure the gravitational acceleration g experienced by the atoms. Using our gravimeter setup, we have measured the local value of g in our laboratory with a sensitivity of 621 μGal for integration time of 1350 s. The use of single laser system keeps our CAG setup simple and compact, and does not require the phase-locking of different lasers.

Zhur. Eksptl'. i Teoret. Fiz.•Jan 1, 2025•2 citations

A Simplified Laser System for Atom Interferometry Based on a Free-Space EOM

Bin Wu, Yingpeng Zhao, Bing Cheng +8 more

In this paper, a compact laser system for 87Rb atom interferometry based on only one free-space electro-optic modulator (EOM) was realized, where repumping and Raman beams were generated with a free-space EOM. In addition, this laser system does not require a laser amplifier compared to fibered EOM since fibered EOM cannot transmit high-power lasers. However, due to the narrow modulation linewidth of free-space EOM, it is impossible to obtain the frequencies of repumping and Raman beams separately, which would lead to some complicated effects. Therefore, a theoretical analysis was carried out to solve this problem, and a new frequency scheme for AI is proposed. For the experiment, the laser system of AI was built up. Moreover, the atomic interference fringes were obtained with a contrast of 20.7% (T = 60 ms) and the fitted phase resolution is approximately 1.25 mrad. The presented laser system could provide a new solution for compact AI systems in the future.

Photonics•Apr 28, 2022•6 citations

Optical single-sideband (OSSB) Raman laser system based on an atomic filter for atom gravimeters

Cong Yi, Yang Chun Zhao, Wei Zhuang +3 more

Phase-modulator-generated laser for Raman transition is widely used in atom gravimeters to simplify a system and improve robustness. However, the induced additional sidebands (ASBs) lead to systematic errors in gravity measurement. This work presents a novel, to our knowledge, method to generate an optical single-sideband (OSSB) laser for Raman transition through phase modulation based on a Faraday anomalous dispersion atomic filter (FADOF). The experimental result indicates that it can reduce the additional sidebands with a signal-to-noise ratio (SNR, the intensity ratio of carrier and unwanted sidebands) of better than 50 dB, and the phase shift caused by ASBs is demonstrated to be effectively suppressed from 358.8 to 2.2 mrad. Furthermore, this system has already been applied on an atom gravimeter to achieve a primary gravity measurement. It shows that the FADOF-based Raman laser system is a new scheme for a compact atom absolute gravimeter.

Optics Letters•Apr 22, 2024•3 citations

Simple and robust architecture of a laser system for atom interferometry

Sumit Sarkar, Raphaël Piccon, Sébastien Merlet +1 more

We report a compact and robust architecture of a versatile laser system that allows the implementation of several advanced atom interferometry techniques, such as Bragg diffraction, Bloch oscillations, or single and double Raman diffraction. A low noise, frequency tunable fiber-laser (λ = ~1560 nm) serves as the seed. A couple of fiber-coupled amplifiers followed by two fibered second-harmonic generators produce a pair of phase-locked, frequency-controllable laser beams at 780 nm. Manipulating frequencies of individual laser beams at λ = 1560 nm before the amplifiers, facilitates achieving a maximum relative detuning of ± 20 MHz, while maintaining a constant output power. We present the scheme to implement Raman spectroscopy using our laser system and discuss its advantages. Finally, the overall performance of the laser setup has been evaluated by realizing interferometers in copropagating Ramsey-Raman and counterpropagating Bragg configuration.

Optics Express•Jan 7, 2022•16 citations

Demonstration of an ultrahigh-sensitivity atom-interferometry absolute gravimeter

Zhong-Kun Hu, Bu-Liang Sun, Xiao‐Chun Duan +5 more

We present an ultrahigh-sensitivity gravimeter based on an ${}^{87}$Rb atom interferometer using stimulated Raman transitions. Compared with our previous work, a two-dimensional magneto-optical trap is added in the new gravimeter to increase the atom number and improve the detection signal-to-noise ratio, and a better optical phase-locked loop system is used to reduce the phase noise of Raman beams. Benefiting from these efforts and the excellent performance of the active vibration isolator, a short-term sensitivity of about 4.2 $\ensuremath{\mu}\text{Gal}/\sqrt{\text{Hz}}$ ($1\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{Gal}=1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ $\text{m}/{\text{s}}^{2}$) is reached, which improves the sensitivity by a factor of 2 compared with the former best reported value. By a modulation experiment, we further indicate that the residual vibration noise contribution is about 1.2 $\ensuremath{\mu}\text{Gal}/\sqrt{\text{Hz}}$, which implies a possible improvement over the present absolute gravity measurement level by about one order of magnitude. Moreover, we demonstrate a calibration experiment to directly evaluate the sub-$\ensuremath{\mu}$Gal resolution of our gravimeter.

Physical Review A•Oct 8, 2013•403 citations

Optimisation of a compact cold-atoms interferometer for gravimetry

Clemens Rammeloo

The work presented in this thesis focusses on the development of a transportable atom-interferometry experiment and a compact fibre laser system towards precision measurements of gravitational acceleration. Interference fringes are shown with clouds of cold 87Rb atoms using co-propagating laser beams to drive stimulated Raman transitions. This is demonstrated both inside and outside of laboratory environments for which an integrated and transportable experiment is constructed. Further improvements are presented that enable the generation of clouds containing 1.7 · 108 atoms at a rate of 2.5 Hz and having a temperature of (7 ± 1) µK. This is largely due to the development of a compact laser system based on all-fibre coupled components. It is demonstrated that the laser system designed here can achieve fast frequency sweeps over 1.8 GHz within 2 ms, making it widely applicable in compact atom-interferometry experiments with rubidium atoms. This is shown by creating a Mach–Zehnder type interferometer with counter-propagating Raman beams, thus enabling measurements of gravitational acceleration. Since the laser system uses only two lasers and one fibre amplifier, a significant reduction in size is achieved, as well as a decrease in the total power consumption of the overall experiment by a third to (162 ± 7) W.

•Jul 1, 2018•1 citation
A compact laser system for a portable 87Rb atom interferometry gravimeter has been demonstrated in this work. This laser system is based on frequency doubling of a single seed laser at the wavelength of 1560 nm. The frequency of the seed laser is controlled by a digital unit with an analog feedback circuit. By using this frequency control method, the frequency of the laser system can be shifted over 1 GHz. Based on this method, the Raman frequency can be locked on the F = 3 → F′ = 4 transition of 85Rb atoms. Moreover, the Raman sideband and the repumping laser are generated by a phase modulator, and it can generate different laser frequencies to meet the requirements of a typical atom interferometer. Additional sidebands in the Raman beam produced from the phase modulator are optimized and reduced, allowing us to observe atom interference with a free evolution time of 320 ms. The control unit including the laser system has been integrated into a box with a volume of 1.5 m × 0.6 m × 0.6 m, and the weight of which is only 150 kg. Using this compact optical scheme, our atomic gravimeter has achieved a sensitivity of 53 μGal/Hz1/2 and a resolution of better than 1 μGal (1 μGal = 1 × 10−8 m/s2) in an integration time of 3000 s.
A cold atom gravimeter (CAG) using a single laser system has been developed. In the setup, the laser cooled Rb atoms are launched in the vertical upward direction and Doppler sensitive two-photon Raman pulse atom interferometry is applied to measure the gravitational acceleration g experienced by the atoms. Using our gravimeter setup, we have measured the local value of g in our laboratory with a sensitivity of 621 μGal for integration time of 1350 s. The use of single laser system keeps our CAG setup simple and compact, and does not require the phase-locking of different lasers.
In this paper, a compact laser system for 87Rb atom interferometry based on only one free-space electro-optic modulator (EOM) was realized, where repumping and Raman beams were generated with a free-space EOM. In addition, this laser system does not require a laser amplifier compared to fibered EOM since fibered EOM cannot transmit high-power lasers. However, due to the narrow modulation linewidth of free-space EOM, it is impossible to obtain the frequencies of repumping and Raman beams separately, which would lead to some complicated effects. Therefore, a theoretical analysis was carried out to solve this problem, and a new frequency scheme for AI is proposed. For the experiment, the laser system of AI was built up. Moreover, the atomic interference fringes were obtained with a contrast of 20.7% (T = 60 ms) and the fitted phase resolution is approximately 1.25 mrad. The presented laser system could provide a new solution for compact AI systems in the future.
Phase-modulator-generated laser for Raman transition is widely used in atom gravimeters to simplify a system and improve robustness. However, the induced additional sidebands (ASBs) lead to systematic errors in gravity measurement. This work presents a novel, to our knowledge, method to generate an optical single-sideband (OSSB) laser for Raman transition through phase modulation based on a Faraday anomalous dispersion atomic filter (FADOF). The experimental result indicates that it can reduce the additional sidebands with a signal-to-noise ratio (SNR, the intensity ratio of carrier and unwanted sidebands) of better than 50 dB, and the phase shift caused by ASBs is demonstrated to be effectively suppressed from 358.8 to 2.2 mrad. Furthermore, this system has already been applied on an atom gravimeter to achieve a primary gravity measurement. It shows that the FADOF-based Raman laser system is a new scheme for a compact atom absolute gravimeter.
We report a compact and robust architecture of a versatile laser system that allows the implementation of several advanced atom interferometry techniques, such as Bragg diffraction, Bloch oscillations, or single and double Raman diffraction. A low noise, frequency tunable fiber-laser (λ = ~1560 nm) serves as the seed. A couple of fiber-coupled amplifiers followed by two fibered second-harmonic generators produce a pair of phase-locked, frequency-controllable laser beams at 780 nm. Manipulating frequencies of individual laser beams at λ = 1560 nm before the amplifiers, facilitates achieving a maximum relative detuning of ± 20 MHz, while maintaining a constant output power. We present the scheme to implement Raman spectroscopy using our laser system and discuss its advantages. Finally, the overall performance of the laser setup has been evaluated by realizing interferometers in copropagating Ramsey-Raman and counterpropagating Bragg configuration.
We present an ultrahigh-sensitivity gravimeter based on an 87{}^{87}87Rb atom interferometer using stimulated Raman transitions. Compared with our previous work, a two-dimensional magneto-optical trap is added in the new gravimeter to increase the atom number and improve the detection signal-to-noise ratio, and a better optical phase-locked loop system is used to reduce the phase noise of Raman beams. Benefiting from these efforts and the excellent performance of the active vibration isolator, a short-term sensitivity of about 4.2 $\ensuremath{\mu}\text{Gal}/\sqrt{\text{Hz}}$ ($1\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{Gal}=1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ m/s2\text{m}/{\text{s}}^{2}m/s2) is reached, which improves the sensitivity by a factor of 2 compared with the former best reported value. By a modulation experiment, we further indicate that the residual vibration noise contribution is about 1.2 $\ensuremath{\mu}\text{Gal}/\sqrt{\text{Hz}}$, which implies a possible improvement over the present absolute gravity measurement level by about one order of magnitude. Moreover, we demonstrate a calibration experiment to directly evaluate the sub-$\ensuremath{\mu}$Gal resolution of our gravimeter.
The work presented in this thesis focusses on the development of a transportable atom-interferometry experiment and a compact fibre laser system towards precision measurements of gravitational acceleration. Interference fringes are shown with clouds of cold 87Rb atoms using co-propagating laser beams to drive stimulated Raman transitions. This is demonstrated both inside and outside of laboratory environments for which an integrated and transportable experiment is constructed. Further improvements are presented that enable the generation of clouds containing 1.7 · 108 atoms at a rate of 2.5 Hz and having a temperature of (7 ± 1) µK. This is largely due to the development of a compact laser system based on all-fibre coupled components. It is demonstrated that the laser system designed here can achieve fast frequency sweeps over 1.8 GHz within 2 ms, making it widely applicable in compact atom-interferometry experiments with rubidium atoms. This is shown by creating a Mach–Zehnder type interferometer with counter-propagating Raman beams, thus enabling measurements of gravitational acceleration. Since the laser system uses only two lasers and one fibre amplifier, a significant reduction in size is achieved, as well as a decrease in the total power consumption of the overall experiment by a third to (162 ± 7) W.