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

Journal of Physics Conference Series

Double-modulation CPT cesium compact clock

Peter Yun, Sinda Mejri, François Tricot, Moustafa Abdel Hafiz, Rodolphe Boudot, Emeric de Clercq, Stéphane Guérandel

Published Jun 1, 2016• 5 citations
Publisher

Abstract

Double-modulation coherent population trapping (CPT) is based on a synchronous modulation of Raman phase and laser polarization, which allows the atomic population to accumulate in a common dark state. The high contrast signal obtained on the clock transition with a relative compact and robust laser system is interesting as basis of a high performance microwave clock. Here we study the parameters of a double-modulation CPT Cs clock working in cw mode. The optimal polarization modulation frequency and cell temperature for maximum contrast of clock transition are investigated. The parameters of the detection are also studied. With the optimal parameters, we observe a CPT signal with contrast of 10% and linewidth of 492 Hz, which is well suited for implementing a cw atomic clock.

DOI
10.1088/1742-6596/723/1/012012

Related papers

Study on double-modulation coherent population trapping resonance

Peter Yun, Sinda Mejri, François Tricot +3 more

Spectroscopy studies of coherent population trapping (CPT) with constructive polarization modulation are presented. In these studies, the effects of modulation frequency and laser intensity on the CPT contrast of the clock transition are investigated. We experimentally show that no CPT transition with ΔmF=2 is excited. Moreover, the constructive polarization modulation CPT signals are observed in both cases, with excited levels F'=3 and F'=4 in the Dl line of Cesium. Our studies show that this scheme, with potential to implement a compact and high performance clock, could also be applied to high pressure buffer gas cell, e.g., chip scale atomic clock.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Apr 1, 2015•1 citation

Coherent population trapping with polarization modulation

Peter Yun, Stéphane Guérandel, Emeric de Clercq

Coherent population trapping (CPT) is extensively studied for future vapor cell clocks of high frequency stability. In the constructive polarization modulation CPT scheme, a bichromatic laser field with polarization and phase synchronously modulated is applied on an atomic medium. A high contrast CPT signal is observed in this so-called double-modulation configuration, due to the fact that the atomic population does not leak to the extreme Zeeman states, and that the two CPT dark states, which are produced successively by the alternate polarizations, add constructively. Here, we experimentally investigate CPT signal dynamics first in the usual configuration, a single circular polarization. The double-modulation scheme is then addressed in both cases: one pulse Rabi interaction and two pulses Ramsey interaction. The impact and the optimization of the experimental parameters involved in the time sequence are reviewed. We show that a simple seven-level model explains the experimental observations. The double-modulation scheme yields a high contrast similar to the one of other high contrast configurations like push-pull optical pumping or crossed linear polarization scheme, with a setup allowing a higher compactness. The constructive polarization modulation is attractive for atomic clock, atomic magnetometer, and high precision spectroscopy applications.

arXiv:1606.04375•Journal of Applied Physics•Jun 23, 2016•20 citations

A compact setup for double-modulation coherent population trapping clock

Peter Yun, François Tricot, David Holleville +2 more

We demonstrate an atomic clock based on double-modulation CPT. With a high contrast CPT signal observed in this scheme, we get a preliminary result of the frequency stability: 4×10-13 at 1 second. It shows the possibility to implement an atomic clock with a compact and robust setup while still maintaining its high performance.

European Frequency and Time Forum•Apr 1, 2016•3 citations

Double-Modulation Coherent Population Trapping Clock

Peter Yun, François Tricot, Claudio Eligio Calosso +5 more

Atomic clocks based on coherent population trapping and constructive polarization modulation are promising for high performance and compact devices. We have demonstrated a cw mode CPT clock with a short-term fractional frequency stability at the level of 3. \pmb2×10-13/√{τ} for a few 100 s integration time. This Double-Modulation CPT technology can be reduced to a miniature and robust setup due to its linear architecture. This clock could find future applications in industry, telecommunications, instrumentation, or global navigation satellite systems.

Conference on Precision Electromagnetic Measurements•Jul 1, 2018•0 citations

Feasibility toward a compact high performance coherent population trapping clock

Peter Yun, François Tricot, Emeric de Clercq +4 more

We demonstrate a vapor-cell atomic-clock prototype based on a continuous-wave interrogation and double-modulation coherent population trapping (DM-CPT) technique. The DM-CPT technique uses a synchronous modulation of polarization and the relative phase of a bichromatic laser beam in order to increase the number of atoms trapped in a dark state, i.e., a nonabsorbing state. The narrow resonance, observed in the transmission of a Cs vapor cell, is used as a narrow frequency discriminator in an atomic clock. A detailed characterization of the CPT resonance versus numerous parameters is reported. A short-term fractional-frequency stability of 3.2×10−13τ−1/2 up to a 100-s averaging time is measured. These performances are more than one order of magnitude better than industrial Rb clocks and are comparable to those of the best laboratory-prototype vapor-cell clocks. The noise-budget analysis shows that the short- and midterm frequency stability is mainly limited by the power fluctuations of the microwave used to generate the bichromatic laser. These preliminary results demonstrate that the DM-CPT technique is well suited for the development of a high-performance atomic clock, with the potential compact and robust setup due to its linear architecture. This clock could find future applications in industry, telecommunications, instrumentation, or global navigation satellite systems.

•Apr 14, 2019•0 citations

Progress of Compact CPT Rb Atomic Clock based on Grating Magneto-Optical Trap

Junyi Duan, Xiaochi Liu, Ning Ru +2 more

The combination of coherent population trapping (CPT) physics and grating magneto-optical trap (GMOT) holds a potential of developing the next generation high performance compact atomic clock. In this work, we aim to build a Rb atomic clock that combining double-modulation coherent population trapping (DM-CPT) in GMOT system. In order to maximize the atoms trapped in clock transition, circularly polarization laser beam is replaced by modulated σ+and σ-beam, with which high-contrast and narrow-linewidth CPT signal could be observed. Also the GMOT system is designed for the interrogation of laser-cooled atoms. This work could provide foundation of high performance compact cold-atom CPT clock.

Conference on Precision Electromagnetic Measurements•Aug 1, 2020•0 citations
Double-modulation coherent population trapping (CPT) is based on a synchronous modulation of Raman phase and laser polarization, which allows the atomic population to accumulate in a common dark state. The high contrast signal obtained on the clock transition with a relative compact and robust laser system is interesting as basis of a high performance microwave clock. Here we study the parameters of a double-modulation CPT Cs clock working in cw mode. The optimal polarization modulation frequency and cell temperature for maximum contrast of clock transition are investigated. The parameters of the detection are also studied. With the optimal parameters, we observe a CPT signal with contrast of 10% and linewidth of 492 Hz, which is well suited for implementing a cw atomic clock.
Spectroscopy studies of coherent population trapping (CPT) with constructive polarization modulation are presented. In these studies, the effects of modulation frequency and laser intensity on the CPT contrast of the clock transition are investigated. We experimentally show that no CPT transition with ΔmF=2 is excited. Moreover, the constructive polarization modulation CPT signals are observed in both cases, with excited levels F'=3 and F'=4 in the Dl line of Cesium. Our studies show that this scheme, with potential to implement a compact and high performance clock, could also be applied to high pressure buffer gas cell, e.g., chip scale atomic clock.
Coherent population trapping (CPT) is extensively studied for future vapor cell clocks of high frequency stability. In the constructive polarization modulation CPT scheme, a bichromatic laser field with polarization and phase synchronously modulated is applied on an atomic medium. A high contrast CPT signal is observed in this so-called double-modulation configuration, due to the fact that the atomic population does not leak to the extreme Zeeman states, and that the two CPT dark states, which are produced successively by the alternate polarizations, add constructively. Here, we experimentally investigate CPT signal dynamics first in the usual configuration, a single circular polarization. The double-modulation scheme is then addressed in both cases: one pulse Rabi interaction and two pulses Ramsey interaction. The impact and the optimization of the experimental parameters involved in the time sequence are reviewed. We show that a simple seven-level model explains the experimental observations. The double-modulation scheme yields a high contrast similar to the one of other high contrast configurations like push-pull optical pumping or crossed linear polarization scheme, with a setup allowing a higher compactness. The constructive polarization modulation is attractive for atomic clock, atomic magnetometer, and high precision spectroscopy applications.
Atomic clocks based on coherent population trapping and constructive polarization modulation are promising for high performance and compact devices. We have demonstrated a cw mode CPT clock with a short-term fractional frequency stability at the level of 3. \pmb2×10-13/√{τ} for a few 100 s integration time. This Double-Modulation CPT technology can be reduced to a miniature and robust setup due to its linear architecture. This clock could find future applications in industry, telecommunications, instrumentation, or global navigation satellite systems.
We demonstrate a vapor-cell atomic-clock prototype based on a continuous-wave interrogation and double-modulation coherent population trapping (DM-CPT) technique. The DM-CPT technique uses a synchronous modulation of polarization and the relative phase of a bichromatic laser beam in order to increase the number of atoms trapped in a dark state, i.e., a nonabsorbing state. The narrow resonance, observed in the transmission of a Cs vapor cell, is used as a narrow frequency discriminator in an atomic clock. A detailed characterization of the CPT resonance versus numerous parameters is reported. A short-term fractional-frequency stability of 3.2×10−13τ−1/2 up to a 100-s averaging time is measured. These performances are more than one order of magnitude better than industrial Rb clocks and are comparable to those of the best laboratory-prototype vapor-cell clocks. The noise-budget analysis shows that the short- and midterm frequency stability is mainly limited by the power fluctuations of the microwave used to generate the bichromatic laser. These preliminary results demonstrate that the DM-CPT technique is well suited for the development of a high-performance atomic clock, with the potential compact and robust setup due to its linear architecture. This clock could find future applications in industry, telecommunications, instrumentation, or global navigation satellite systems.
The combination of coherent population trapping (CPT) physics and grating magneto-optical trap (GMOT) holds a potential of developing the next generation high performance compact atomic clock. In this work, we aim to build a Rb atomic clock that combining double-modulation coherent population trapping (DM-CPT) in GMOT system. In order to maximize the atoms trapped in clock transition, circularly polarization laser beam is replaced by modulated σ+and σ-beam, with which high-contrast and narrow-linewidth CPT signal could be observed. Also the GMOT system is designed for the interrogation of laser-cooled atoms. This work could provide foundation of high performance compact cold-atom CPT clock.