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

Tai Hezi Kexue Yudianzi Xinxi Xuebao

A design and implementation of miniature CPT atomic clock based on ~(85)Rb

Duan We

Published Jan 1, 2015• 0 citations
OpenAlex

Abstract

A Coherent Population Trapping(CPT) atomic clock servo control circuit is designed based on the CPT phenomenon of 85 Rb. Taking MSP430 chip as a platform, combining with the physical device made up of Vecsel laser, photoelectric detector, and small 85 Rb vapor cell, a miniature atomic clock with the high-performance, high stability, low power consumption and small size is implemented. The volume is 31 cm3 and the power consumption is 660 m W. The frequency stability of 10 MHz measured is 2×10-10/s, 4×10-11/1 000 s. Full-hyperfine-splitting frequency modulation is used to improve the frequency stability.

Related papers

Frequency Stability of Atomic Clocks Based on Coherent Population Trapping Resonance in 85 Rb

Lu Liu, Guo Tao, Ke Deng +3 more

An atomic clock system based on coherent population trapping (CPT) resonance in 85 Rb is reported, while most past works about the CPT clock are in 87 Rb. A new modulation method (full-hyperfine-frequency-splitting modulation) is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in 85 Rb. The experimental results show that the short-term frequency stability of the CPT clock in 85 Rb is in the order of 10 −10 /s and the long-term frequency stability can achieve 1.5 × 10 −11 /80000 s, which performs as well as 87 Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of 85 Rb indicates that an atomic clock based on CPT in 85 Rb should be a promising candidate for making the chip scale atomic clock.

Chinese Physics Letters•Jun 28, 2007•9 citations

85Rb Coherent-Population-Trapping Atomic Clock with Low Power Consumption

Shigeyoshi Goka

In this paper, the investigation of a 85 Rb coherent-population-trapping (CPT) atomic clock for low-power operation is described. The modulation profiles and CPT resonances for both 85 Rb and 87 Rb, the long-term frequency stabilities of the CPT resonance for both, and the feasibility of switching between low-power and high-stability operation modes are presented. The choice of 85 Rb rather than conventional 87 Rb is dictated by the lower ground-state hyperfine-splitting frequency, which leads to less than one-half the required RF power and more effective RF-related circuit designs. CPT resonances for both 85 Rb and 87 Rb can be observed separately in the same natural mixture Rb gas cell, and the linewidth is less than 120 Hz in both cases. The long-term frequency stabilities are <4.0 ×10 -12 /day for 85 Rb and <3.5 ×10 -12 /day for 87 Rb. These results indicate that a 85 Rb CPT atomic clock has a long-term stability of ∼4.0 ×10 -12 /day and consumes about one-half the RF power of a 87 Rb equivqlent. In addition, it is possible to switch between low-power and high-stability operation modes by changing the RF frequency and power.

Japanese Journal of Applied Physics•Aug 20, 2009•8 citations

Study on characteristics of coherent population trapping spectral line for chip-scale atomic clock

Yi Yin, Yi Zhang, Tan Bo-Zhong +2 more

To Obtain an appropriate coherent population trapping (CPT) signal through a miniature atomic vapor cell is one of the key steps to implement a chip-scale atomic clock (CSAC). In the present experiment, the high S/N differential CPT spectral line has been achieved with a miniature atomic vapor cell through modulating the laser and extracting 87Rb atom laser interacting signal using the phase sensitive demodulation technique. With the spectral line, the dependence of CPT signal on the working parameters and the dependence of frequency stability of CSAC on the quality of the CPT signal have been studied; the obtained experimental results agree well with the theoretical prediction, which can be used as the recommended working parameters for CSAC. The methods exploited in the experiment can be implemented in the resource of a CSAC, therefore this experiment explores for CSAC the practical approaches of performance optimization.

Acta Physica Sinica•Jan 1, 2015•1 citation

Atomic Frequency Standard based on Coherent Population Trapping in Rb-87 Atoms for Space Application

Pragya Tiwari, Manjula Ramachandra, Madan Mohan Kandpal +11 more

Space-borne atomic frequency standards demand a high level of performance and stability throughout the mission life in the harsh environment of space. Recently, atomic clocks employing Coherent Population Trapping (CPT), a quantum interference phenomenon in alkali atoms, have shown much promise for space application. This paper presents the development and realization of compact and reliable CPT atomic clock for ISRO's navigational satellites. In our approach, quantum interference in Rb-87 atoms are pursued for obtaining the clock resonance, owing to their larger ground state hyperfine transition energy (higher Q-factor). Quantum interference is realized by generating two resonant optical laser fields from a VCSEL diode by modulating its drive current at RF frequency which corresponds to the ground state hyperfine separation in Rb-87 atoms. The emission frequency of the laser diode is stabilized by locking it with respect to the D1 hyperfine transition with the help of a servo control loop, thereby the instabilities associated with laser frequency fluctuations are minimized. The resulting CPT resonance (<;kHz) as shown in Figure 1 is used as reference to stabilize the crystal oscillator frequency (10 MHz) that serves both as clock output and seed for generating the RF field.

URSI Asia-Pacific Radio Science Conference•Mar 1, 2019•0 citations

Low power 85Rb CPT atomic clock

Shigeyoshi Goka, Okura Taisuke, Moroyama Munetake +1 more

This paper outlines the features of the85Rb vapor cell atomic clock, the coherent population trapping (CPT) resonance in an85Rb/87Rb mixed vapor cell, and the results of the frequency stabilities of a pilot system. The experiments were performed with a sealed vapor cell containing a natural mixture of Rb isotopes and a buffer gas. Excitation of the CPT resonance was accomplished using a vertical-cavity surface-emitting laser modulated at 1.5, 3.0, 3.4 and 6.8 GHz, which corresponded to the full- and half-ground-state hyperfine frequencies of85Rb and87Rb. The results show that the CPT resonances at both85Rb and87Rb can be observed separately. The frequency stabilities of the output signals for each CPT resonance were ≪ 10x10−12/day for85Rb and ≪ 6x10−12/day for87Rb. In addition, the RF modulation signal power for85Rb was 1.1 dB less than that of87Rb, which was 3.4GHz.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•May 1, 2008•2 citations

85Rb D1-line CPT atomic clock with low power consumption

Shigeyoshi Goka

This paper describes the investigation of a85Rb D1-line coherent population trapping (CPT) atomic clock with a Rb gas-cell containing a natural mixture of Rb atoms and buffer gas. The choice of85Rb rather than conventional87Rb is dictated by the lower ground-state hyperfine-splitting frequency, which leads to less than one-half the required RF power and more effective RF-related circuit designs. In this paper, the modulation profiles, the CPT resonances, and the long-term frequency stabilities of the CPT resonance for85Rb D1 and D2 lines are presented. The frequency deviations for D1 and D2 lines are measured using a same experimental setup except for VCSEL wavelength and RF power. The Allan deviations, estimated from the frequency deviations, are-12/day for D1 line and-12/day for D2 line. In the case of D1 excitation, required RF frequency is 1.5 GHz and its power is only -8.0 dBm.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Apr 1, 2009•0 citations
A Coherent Population Trapping(CPT) atomic clock servo control circuit is designed based on the CPT phenomenon of 85 Rb. Taking MSP430 chip as a platform, combining with the physical device made up of Vecsel laser, photoelectric detector, and small 85 Rb vapor cell, a miniature atomic clock with the high-performance, high stability, low power consumption and small size is implemented. The volume is 31 cm3 and the power consumption is 660 m W. The frequency stability of 10 MHz measured is 2×10-10/s, 4×10-11/1 000 s. Full-hyperfine-splitting frequency modulation is used to improve the frequency stability.
An atomic clock system based on coherent population trapping (CPT) resonance in 85 Rb is reported, while most past works about the CPT clock are in 87 Rb. A new modulation method (full-hyperfine-frequency-splitting modulation) is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in 85 Rb. The experimental results show that the short-term frequency stability of the CPT clock in 85 Rb is in the order of 10 −10 /s and the long-term frequency stability can achieve 1.5 × 10 −11 /80000 s, which performs as well as 87 Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of 85 Rb indicates that an atomic clock based on CPT in 85 Rb should be a promising candidate for making the chip scale atomic clock.
In this paper, the investigation of a 85 Rb coherent-population-trapping (CPT) atomic clock for low-power operation is described. The modulation profiles and CPT resonances for both 85 Rb and 87 Rb, the long-term frequency stabilities of the CPT resonance for both, and the feasibility of switching between low-power and high-stability operation modes are presented. The choice of 85 Rb rather than conventional 87 Rb is dictated by the lower ground-state hyperfine-splitting frequency, which leads to less than one-half the required RF power and more effective RF-related circuit designs. CPT resonances for both 85 Rb and 87 Rb can be observed separately in the same natural mixture Rb gas cell, and the linewidth is less than 120 Hz in both cases. The long-term frequency stabilities are <4.0 ×10 -12 /day for 85 Rb and <3.5 ×10 -12 /day for 87 Rb. These results indicate that a 85 Rb CPT atomic clock has a long-term stability of ∼4.0 ×10 -12 /day and consumes about one-half the RF power of a 87 Rb equivqlent. In addition, it is possible to switch between low-power and high-stability operation modes by changing the RF frequency and power.
To Obtain an appropriate coherent population trapping (CPT) signal through a miniature atomic vapor cell is one of the key steps to implement a chip-scale atomic clock (CSAC). In the present experiment, the high S/N differential CPT spectral line has been achieved with a miniature atomic vapor cell through modulating the laser and extracting 87Rb atom laser interacting signal using the phase sensitive demodulation technique. With the spectral line, the dependence of CPT signal on the working parameters and the dependence of frequency stability of CSAC on the quality of the CPT signal have been studied; the obtained experimental results agree well with the theoretical prediction, which can be used as the recommended working parameters for CSAC. The methods exploited in the experiment can be implemented in the resource of a CSAC, therefore this experiment explores for CSAC the practical approaches of performance optimization.
Space-borne atomic frequency standards demand a high level of performance and stability throughout the mission life in the harsh environment of space. Recently, atomic clocks employing Coherent Population Trapping (CPT), a quantum interference phenomenon in alkali atoms, have shown much promise for space application. This paper presents the development and realization of compact and reliable CPT atomic clock for ISRO's navigational satellites. In our approach, quantum interference in Rb-87 atoms are pursued for obtaining the clock resonance, owing to their larger ground state hyperfine transition energy (higher Q-factor). Quantum interference is realized by generating two resonant optical laser fields from a VCSEL diode by modulating its drive current at RF frequency which corresponds to the ground state hyperfine separation in Rb-87 atoms. The emission frequency of the laser diode is stabilized by locking it with respect to the D1 hyperfine transition with the help of a servo control loop, thereby the instabilities associated with laser frequency fluctuations are minimized. The resulting CPT resonance (<;kHz) as shown in Figure 1 is used as reference to stabilize the crystal oscillator frequency (10 MHz) that serves both as clock output and seed for generating the RF field.
This paper outlines the features of the85Rb vapor cell atomic clock, the coherent population trapping (CPT) resonance in an85Rb/87Rb mixed vapor cell, and the results of the frequency stabilities of a pilot system. The experiments were performed with a sealed vapor cell containing a natural mixture of Rb isotopes and a buffer gas. Excitation of the CPT resonance was accomplished using a vertical-cavity surface-emitting laser modulated at 1.5, 3.0, 3.4 and 6.8 GHz, which corresponded to the full- and half-ground-state hyperfine frequencies of85Rb and87Rb. The results show that the CPT resonances at both85Rb and87Rb can be observed separately. The frequency stabilities of the output signals for each CPT resonance were ≪ 10x10−12/day for85Rb and ≪ 6x10−12/day for87Rb. In addition, the RF modulation signal power for85Rb was 1.1 dB less than that of87Rb, which was 3.4GHz.
This paper describes the investigation of a85Rb D1-line coherent population trapping (CPT) atomic clock with a Rb gas-cell containing a natural mixture of Rb atoms and buffer gas. The choice of85Rb rather than conventional87Rb is dictated by the lower ground-state hyperfine-splitting frequency, which leads to less than one-half the required RF power and more effective RF-related circuit designs. In this paper, the modulation profiles, the CPT resonances, and the long-term frequency stabilities of the CPT resonance for85Rb D1 and D2 lines are presented. The frequency deviations for D1 and D2 lines are measured using a same experimental setup except for VCSEL wavelength and RF power. The Allan deviations, estimated from the frequency deviations, are-12/day for D1 line and-12/day for D2 line. In the case of D1 excitation, required RF frequency is 1.5 GHz and its power is only -8.0 dBm.