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:2207.05222

Temperature shift suppression scheme for two-photon two-color rubidium vapor clocks

Tin Nghia Nguyen, T. R. Schibli

Published Jul 11, 2022• 0 citations
arXivHTMLPDF

Abstract

We propose a new scheme for interrogating a warm rubidium vapor using two different clock lasers. Performance-wise, this approach is distinctly different from the recently proposed two-color two-photon rubidium clocks as our scheme does not trade off the AC Stark suppression against an increased sensitivity to the cell-temperature/pressure. Instead, our approach compensates all, the AC-Stark shift and the temperature & pressure-induced frequency shifts. The proposed scheme also makes use of the modulation transfer technique, which enables a two-orders of magnitude increase in the signal-to-noise ratio compared to traditional clocks that rely on fluorescence measurements.

DOI
10.48550/arxiv.2207.05222

Related papers

Temperature-shift-suppression scheme for two-photon two-color rubidium vapor clocks

Tin Nghia Nguyen, T. R. Schibli

We propose a scheme for interrogating a warm rubidium vapor using two different clock lasers. Performance wise, this approach is distinctly different from the recently proposed two-color two-photon rubidium clocks as our scheme does not trade off the ac Stark suppression against an increased sensitivity to the cell temperature or pressure. Instead, our approach compensates both the ac Stark shift and the temperature and pressure-induced frequency shifts. The proposed scheme also makes use of the modulation transfer technique, which enables a two orders of magnitude increase in the signal-to-noise ratio compared to traditional clocks that rely on fluorescence measurements.

Physical Review A•Nov 3, 2022•4 citations

Suppressing the light shift in a two-photon rubidium optical frequency reference

Yorick Andeweg, John E. Kitching, Matthew T. Hummon

The two-photon transition in rubidium is an attractive candidate for use in the next generation of field-deployable atomic clocks and frequency references. However, this transition is known to suffer from a large AC Stark shift, through which fluctuations in the intensity of the interrogation laser cause fluctuations of the clock frequency, often limiting long-term stability. We implement an interrogation protocol known as the auto-compensated shift (ACS) in a two-photon rubidium optical frequency reference, reducing its sensitivity to optical intensity fluctuations by a factor of 1000. ACS alleviates the tradeoff between short-term and long-term stability imposed by the light shift and enables us to simultaneously achieve a fractional instability of 3 x 10^-14 at an integration time of 1 s and 2 x 10^-14 at an integration time of 10,000 s. We also examine a stability limit imposed on clocks using ACS by frequency noise on the laser.

Optical and Quantum Sensing and Precision Metrology II•Mar 5, 2026•0 citations

A frequency shift compensation method for light shift and vapor-cell temperature shift in atomic clocks

Dou Li, Kangqi Liu, Linzhen Zhao +1 more

Light shift and vapor-cell temperature shift are the two most significant factors dominating the long-term instability of compact atomic clocks. Due to the different physical mechanisms, there is not yet a solution that can effectively suppress the frequency shifts induced by these two effects. Here, we propose a 'resonance-offset' locking approach that compensates for the two physical frequency shifts. In this approach, the additional offset locking shift can effectively counteract the atomic resonance shifts arising from changes in vapor-cell temperature and light power, reducing the net impact on the clock's frequency to nearly zero. We have demonstrated this strategy on the 778 nm Rubidium two-photon optical frequency standard, successfully compensating for light shift and cell-temperature shift, respectively. This general method is particularly appealing for compact vapor-cell microwave and optical atomic clocks designed for the excellent stability rather than accuracy.

arXiv:2405.14281•May 23, 2024•0 citations

A Comprehensive Review of Rubidium Two-Photon Vapor Cell Optical Clock: Long-Term Performance Limitations and Potential Improvements

Asagwegbe C. Obaze-Adeleke, Bryan Semon, Thejesh Bandi

Two-photon vapor cell-based optical clocks are strong candidates for next-generation portable atomic standards, offering simplicity, compactness, and high performance. Their narrow clock transitions with counter-propagating beams enable first-order Doppler-free operation. However, systematic perturbations such as the AC Stark shift, temperature-induced shift, and drifts resulting from the laser system pose challenges cause instabilities to medium- to long-term performance. This paper provides a comprehensive overview of Rb two-photon vapor cell optical standards, focusing on the long-term performance-limiting effects and potential mitigation strategies, aiming for clock stabilities better than 1 × 10−15 over the averaging time of a day and beyond.

Photonics•May 20, 2025•10 citations

Two-photon Optical Frequency Reference with Active ac Stark Shift Cancellation

Vladislav P. Gerginov, K. Beloy

The two-photon optical transition in rubidium offers a means to a simple, stable optical frequency reference. Here accuracy is limited by frequency drift due to fluctuations in light intensity, while stability is limited by the signal-to-noise ratio of detection. In its traditional implementation there is a tradeoff between accuracy and stability, set by the technical ability to control light intensity. This study uses a two-color excitation scheme for cancellation of light-induced frequency drifts, and replaces fluorescence with absorption in detection, allowing significant improvement of the standard's stability and accuracy.

arXiv:1808.01373•Physical Review Applied•Jul 30, 2018•36 citations

Active compensation of the ac Stark shift in a two-photon rubidium optical frequency reference using power modulation

Yorick Andeweg, John E. Kitching, Matthew T. Hummon

We implement a feedback protocol to suppress the ac Stark shift in a two-photon rubidium optical frequency reference, reducing its sensitivity to optical power variations by a factor of 1000. This method alleviates the tradeoff between short-term and long-term stability imposed by the ac Stark shift, enabling us to simultaneously achieve instabilities of 3 × 10 − 14 at 1 s and 2 × 10 − 14 at 10 4 s. We also quantitatively describe, and experimentally explore, a stability limit imposed on clocks using this method by frequency noise on the local oscillator.

arXiv:2511.19702•Physical Review Applied•Feb 6, 2026•1 citation
We propose a new scheme for interrogating a warm rubidium vapor using two different clock lasers. Performance-wise, this approach is distinctly different from the recently proposed two-color two-photon rubidium clocks as our scheme does not trade off the AC Stark suppression against an increased sensitivity to the cell-temperature/pressure. Instead, our approach compensates all, the AC-Stark shift and the temperature & pressure-induced frequency shifts. The proposed scheme also makes use of the modulation transfer technique, which enables a two-orders of magnitude increase in the signal-to-noise ratio compared to traditional clocks that rely on fluorescence measurements.
We propose a scheme for interrogating a warm rubidium vapor using two different clock lasers. Performance wise, this approach is distinctly different from the recently proposed two-color two-photon rubidium clocks as our scheme does not trade off the ac Stark suppression against an increased sensitivity to the cell temperature or pressure. Instead, our approach compensates both the ac Stark shift and the temperature and pressure-induced frequency shifts. The proposed scheme also makes use of the modulation transfer technique, which enables a two orders of magnitude increase in the signal-to-noise ratio compared to traditional clocks that rely on fluorescence measurements.
The two-photon transition in rubidium is an attractive candidate for use in the next generation of field-deployable atomic clocks and frequency references. However, this transition is known to suffer from a large AC Stark shift, through which fluctuations in the intensity of the interrogation laser cause fluctuations of the clock frequency, often limiting long-term stability. We implement an interrogation protocol known as the auto-compensated shift (ACS) in a two-photon rubidium optical frequency reference, reducing its sensitivity to optical intensity fluctuations by a factor of 1000. ACS alleviates the tradeoff between short-term and long-term stability imposed by the light shift and enables us to simultaneously achieve a fractional instability of 3 x 10^-14 at an integration time of 1 s and 2 x 10^-14 at an integration time of 10,000 s. We also examine a stability limit imposed on clocks using ACS by frequency noise on the laser.
Light shift and vapor-cell temperature shift are the two most significant factors dominating the long-term instability of compact atomic clocks. Due to the different physical mechanisms, there is not yet a solution that can effectively suppress the frequency shifts induced by these two effects. Here, we propose a 'resonance-offset' locking approach that compensates for the two physical frequency shifts. In this approach, the additional offset locking shift can effectively counteract the atomic resonance shifts arising from changes in vapor-cell temperature and light power, reducing the net impact on the clock's frequency to nearly zero. We have demonstrated this strategy on the 778 nm Rubidium two-photon optical frequency standard, successfully compensating for light shift and cell-temperature shift, respectively. This general method is particularly appealing for compact vapor-cell microwave and optical atomic clocks designed for the excellent stability rather than accuracy.
Two-photon vapor cell-based optical clocks are strong candidates for next-generation portable atomic standards, offering simplicity, compactness, and high performance. Their narrow clock transitions with counter-propagating beams enable first-order Doppler-free operation. However, systematic perturbations such as the AC Stark shift, temperature-induced shift, and drifts resulting from the laser system pose challenges cause instabilities to medium- to long-term performance. This paper provides a comprehensive overview of Rb two-photon vapor cell optical standards, focusing on the long-term performance-limiting effects and potential mitigation strategies, aiming for clock stabilities better than 1 × 10−15 over the averaging time of a day and beyond.
The two-photon optical transition in rubidium offers a means to a simple, stable optical frequency reference. Here accuracy is limited by frequency drift due to fluctuations in light intensity, while stability is limited by the signal-to-noise ratio of detection. In its traditional implementation there is a tradeoff between accuracy and stability, set by the technical ability to control light intensity. This study uses a two-color excitation scheme for cancellation of light-induced frequency drifts, and replaces fluorescence with absorption in detection, allowing significant improvement of the standard's stability and accuracy.
We implement a feedback protocol to suppress the ac Stark shift in a two-photon rubidium optical frequency reference, reducing its sensitivity to optical power variations by a factor of 1000. This method alleviates the tradeoff between short-term and long-term stability imposed by the ac Stark shift, enabling us to simultaneously achieve instabilities of 3 × 10 − 14 at 1 s and 2 × 10 − 14 at 10 4 s. We also quantitatively describe, and experimentally explore, a stability limit imposed on clocks using this method by frequency noise on the local oscillator.