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

Physical Review A

Frequency shift caused by the line-shape asymmetry of the resonance of coherent population trapping

Valeriy I. Yudin, M. Yu. Basalaev, А. В. Тайченачев, Прудников Олег Николаевич, Daba A. Radnatarov, Sergey M Kobtsev, S M Ignatovich, Mikhail N Skvortsov

Published Jul 10, 2023• 17 citations
Publisher

Abstract

We theoretically study the frequency shift in atomic clocks caused by the line-shape asymmetry of coherent population trapping (CPT) resonance in a bichromatic laser field. This asymmetry arises due to the inequality of the resonant spectral components and nonzero one-photon detuning. The line-shape-asymmetry-induced shift depends on the intensity of the resonant fields, which leads to a degradation in long-term stability due to fluctuations of the laser field parameters. A frequency stabilization based on the harmonic modulation of two-photon detuning is considered. It is shown that the use of a high-frequency modulation (compared to the CPT resonance width, i.e., the Pound-Drever-Hall regime) makes it possible to significantly suppress this shift (by one to two orders of magnitude).

DOI
10.1103/physreva.108.013103

Related papers

A nonlinear frequency shift caused by asymmetry of the coherent population trapping resonance: a generalization

Eugene A. Tsygankov, Dmitry S. Chuchelov, Maria I. Vaskovskaya +3 more

We investigate the coherent population trapping resonance induced by a polychromatic optical field with an asymmetric spectrum, i.e., whose sidebands equidistant from the carrier have unequal powers. A situation is considered where a modulation is used to provide the so-called in-phase and quadrature signals in the optical field's transmission, which are used for stabilization of the local oscillator's frequency in chip-scale atomic clocks. In a general case, the frequencies of the signals nonlinearly depend on the optical field's intensity due to the asymmetry of the resonance. In this work, we demonstrate a) that this effect stems from a multi-peak structure of the resonance; b) a linear dependence of the frequency on the optical field's intensity at high modulation values; c) that the regime of the resolved structure has more advantages than suppression of the frequency shift due to the spectrum asymmetry.

arXiv:2311.17229•Nov 28, 2023•0 citations

Nonlinear frequency shift caused by asymmetry of the multipeak coherent population trapping resonance

Eugene A. Tsygankov, Dmitry S. Chuchelov, Maria I. Vaskovskaya +3 more

We study the coherent population trapping resonance induced by the radiation of a microwave-current-modulated diode laser. The situation is considered when a harmonic phase modulation of the microwave field is used to generate the error signal for the frequency stabilization of atomic clocks. We demonstrate that in this case the resonance acquires a multipeak structure. If it is asymmetric and the components of the multipeak structure are not fully resolved, then the resonance frequency nonlinearly depends on the laser field intensity. The peaks become separated at an increase in the frequency of the phase modulation, providing a linear dependence of the frequency on the intensity of the laser field. This theoretical prediction is confirmed experimentally. Other advantages of the high-frequency modulation regime are also discussed.

Physical Review A•May 2, 2024•12 citations

Field Shift of Coherent Population Trapping Resonance Taking into Account Spatial Inhomogeneity of the Light Beam

Д. В. Коваленко, Valeriy I. Yudin, M. Yu. Basalaev +3 more

We study the field shift of coherent population trapping (CPT) resonance excited by a bichromatic field in an open Λ system with account for the Gaussian profile of the laser radiation intensity. Two methods for error signal formation are considered: the harmonic frequency modulation and the step phase modulation (phase jumps). It is shown that the spatial inhomogeneity of the light beam leads to an essentially nonlinear dependence of the error signal shift on the laser radiation intensity. We propose an approach for the linearization of this dependence, which is important for the development of methods for suppressing the field shift in atomic clocks based on CPT resonances.

Журнал Экспериментальной и Теоретической Физики•Dec 15, 2023•0 citations

Modulation-induced frequency shifts in a coherent-population-trapping-based atomic clock

David F. Phillips, Irina V. Novikova, Christine Y.-T. Wang +2 more

We investigate systematic errors associated with a common modulation technique used for phase-sensitive detection of a coherent-population-trapping (CPT) resonance. In particular, we show that modification of the CPT resonance line shape due to the presence of off-resonant fields leads to frequency shifts that may limit the stability of CPT-based atomic clocks. We also demonstrate that an alternative demodulation technique greatly reduces these effects.

arXiv:physics/0404076•Journal of the Optical Society of America B•Feb 1, 2005•25 citations

Continuous light-shift correction in modulated coherent population trapping clocks

Vishal Shah, Vladislav P. Gerginov, Peter D. D. Schwindt +3 more

The authors demonstrate a simple technique to significantly improve the long-term frequency stability of atomic clocks based on coherent population trapping (CPT). In this technique, the CPT fields are created by a modulated diode laser and a slow servo is used to actively tune the laser modulation index to a value where the light shift vanishes. The observed clock frequency at this modulation index is given by the rubidium hyperfine frequency when no light fields are present, and this makes the clock frequency largely insensitive to variations in laser properties. In addition to reducing stringent requirements on the long-term stabilities of laser temperature, laser frequency, and rf modulation power, this technique may also significantly reduce frequency drifts related to laser aging. In the experiment, they demonstrate improvement by over one order of magnitude in the stability of a clock that is limited by light-shift-induced frequency drifts.

Applied Physics Letters•Oct 9, 2006•72 citations

Field Shift of Coherent Population Trapping Resonance Taking into Account Spatial Inhomogeneity of the Light Beam

Д. В. Коваленко, Valeriy I. Yudin, M. Yu. Basalaev +3 more

Abstract We study the field shift of coherent population trapping (CPT) resonance excited by a bichromatic field in an open Λ system with account for the Gaussian profile of the laser radiation intensity. Two methods for error signal formation are considered: the harmonic frequency modulation and the step phase modulation (phase jumps). It is shown that the spatial inhomogeneity of the light beam leads to an essentially nonlinear dependence of the error signal shift on the laser radiation intensity. We propose an approach for the linearization of this dependence, which is important for the development of methods for suppressing the field shift in atomic clocks based on CPT resonances.

Journal of Experimental and Theoretical Physics•Aug 1, 2023•0 citations
We theoretically study the frequency shift in atomic clocks caused by the line-shape asymmetry of coherent population trapping (CPT) resonance in a bichromatic laser field. This asymmetry arises due to the inequality of the resonant spectral components and nonzero one-photon detuning. The line-shape-asymmetry-induced shift depends on the intensity of the resonant fields, which leads to a degradation in long-term stability due to fluctuations of the laser field parameters. A frequency stabilization based on the harmonic modulation of two-photon detuning is considered. It is shown that the use of a high-frequency modulation (compared to the CPT resonance width, i.e., the Pound-Drever-Hall regime) makes it possible to significantly suppress this shift (by one to two orders of magnitude).
We investigate the coherent population trapping resonance induced by a polychromatic optical field with an asymmetric spectrum, i.e., whose sidebands equidistant from the carrier have unequal powers. A situation is considered where a modulation is used to provide the so-called in-phase and quadrature signals in the optical field's transmission, which are used for stabilization of the local oscillator's frequency in chip-scale atomic clocks. In a general case, the frequencies of the signals nonlinearly depend on the optical field's intensity due to the asymmetry of the resonance. In this work, we demonstrate a) that this effect stems from a multi-peak structure of the resonance; b) a linear dependence of the frequency on the optical field's intensity at high modulation values; c) that the regime of the resolved structure has more advantages than suppression of the frequency shift due to the spectrum asymmetry.
We study the coherent population trapping resonance induced by the radiation of a microwave-current-modulated diode laser. The situation is considered when a harmonic phase modulation of the microwave field is used to generate the error signal for the frequency stabilization of atomic clocks. We demonstrate that in this case the resonance acquires a multipeak structure. If it is asymmetric and the components of the multipeak structure are not fully resolved, then the resonance frequency nonlinearly depends on the laser field intensity. The peaks become separated at an increase in the frequency of the phase modulation, providing a linear dependence of the frequency on the intensity of the laser field. This theoretical prediction is confirmed experimentally. Other advantages of the high-frequency modulation regime are also discussed.
We study the field shift of coherent population trapping (CPT) resonance excited by a bichromatic field in an open Λ system with account for the Gaussian profile of the laser radiation intensity. Two methods for error signal formation are considered: the harmonic frequency modulation and the step phase modulation (phase jumps). It is shown that the spatial inhomogeneity of the light beam leads to an essentially nonlinear dependence of the error signal shift on the laser radiation intensity. We propose an approach for the linearization of this dependence, which is important for the development of methods for suppressing the field shift in atomic clocks based on CPT resonances.
The authors demonstrate a simple technique to significantly improve the long-term frequency stability of atomic clocks based on coherent population trapping (CPT). In this technique, the CPT fields are created by a modulated diode laser and a slow servo is used to actively tune the laser modulation index to a value where the light shift vanishes. The observed clock frequency at this modulation index is given by the rubidium hyperfine frequency when no light fields are present, and this makes the clock frequency largely insensitive to variations in laser properties. In addition to reducing stringent requirements on the long-term stabilities of laser temperature, laser frequency, and rf modulation power, this technique may also significantly reduce frequency drifts related to laser aging. In the experiment, they demonstrate improvement by over one order of magnitude in the stability of a clock that is limited by light-shift-induced frequency drifts.
Abstract We study the field shift of coherent population trapping (CPT) resonance excited by a bichromatic field in an open Λ system with account for the Gaussian profile of the laser radiation intensity. Two methods for error signal formation are considered: the harmonic frequency modulation and the step phase modulation (phase jumps). It is shown that the spatial inhomogeneity of the light beam leads to an essentially nonlinear dependence of the error signal shift on the laser radiation intensity. We propose an approach for the linearization of this dependence, which is important for the development of methods for suppressing the field shift in atomic clocks based on CPT resonances.