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 Optics A Pure and Applied Optics

Microfabricated atomic clocks and magnetometers

Svenja A. Knappe, Peter D. D. Schwindt, Vladislav P. Gerginov, Vishal Shah, Li‐Anne Liew, John Moreland, H. G. Robinson, Leo W. Hollberg, John E. Kitching

Published May 31, 2006• 69 citations
Publisher

Abstract

We demonstrate the critical subsystems of a compact atomic clock based on a microfabricated physics package. The clock components have a total volume below 10 cm3, a fractional frequency instability of 6 × 10−10/τ1/2, and consume 200 mW of power. The physics package is easily adapted to function as a magnetometer with sensitivity below 50 pT Hz−1/2 at 10 Hz.

DOI
10.1088/1464-4258/8/7/s04

Related papers

Microfabricated atomic clocks and magnetometers

Svenja A. Knappe, Peter D. D. Schwindt, Vladislav P. Gerginov +6 more

We demonstrate the critical subsystems of compact atomic clocks and magnetometers based on microfabricated physics packages. The clock components have a volume below 5 cm3, a fractional frequency instability below 6times10-10tau1/2, and consume 200 mW of power. The magnetometer has a sensitivity below 40pT/Hz1/2at 50 Hz

IEEE/LEOS International Conference on Optical MEMS•Oct 11, 2006•2 citations

Microfabricated Atomic Magnetometer

Peter D. D. Schwindt, Svenja A. Knappe, Vishal Shah +4 more

Using the techniques of microelectromechanical systems, we are developing chip-scale atomic sensors based on laser excitation of alkali atoms. Recently, we demonstrated a magnetometer physics package based on coherent population trapping that had a sensitivity of 50 pT/Hzfrac12at 10 Hz, had a volume of 12 mm3, and used 195 mW of power as presented by Schwindt et al. (2004). To improve the sensitivity and reduce the power consumption of the magnetometer, we are evaluating other methods of interrogating the atoms for use in microfabricated devices. One of these methods uses frequency modulated nonlinear magneto-optical rotation (FM NMOR). We demonstrate that an FM NMOR magnetometer can be made to self-oscillate, offering simple construction and low power consumption

Proceedings of IEEE Sensors/Proceedings of IEEE Sensors ...•Mar 22, 2006•1 citation

Compact atomic clock based on coherent populationtrapping

J. Kitching, Leo W. Hollberg, S. Knappe +1 more

A simple, compact, low-power physics package for a vapour-cell atomic clock is described. The device measures 6.6 × 1.6 × 1.3 cm and dissipates less than 30 mW of electrical power without thermal control. The instability is 1.3 × 10-10/√[τ/(s)] for integration times τ below 100 s. Applications for this device include distributed telecommunications systems, advanced global positioning system (GPS) receivers and laboratory instrumentation.

Electronics Letters•Nov 22, 2001•56 citations

The Chip-Scale Atomic Clock - Low-Power Physics Package

Robert Lutwak, Jinyi Deng, William Riley +7 more

We have undertaken a development effort to produce a prototype chip-scale atomic clock (CSAC). The design goals include short-term stability, with a total power consumption of less than 30 mW and overall device volume <1 cubic cm. The stringent power requirement dominates the physics package architecture, necessarily dictating a small volume gaseous atomic ensemble interrogated by a low-power semiconductor laser. At PTTI 2002 and PTTI 2003, we reported on laboratory experiments that underlie the fundamental architecture of our CSAC, based on interrogation of the cesium D1 transition by the technique of coherent population trapping (CPT). In the past year, the development effort has shifted from fundamental research and feasibility investigation to engineering and prototype development. In this paper, we report on the design of a rugged and compact physics package that is expected to exceed the ultimate performance and power requirements of the CSAC.

•Dec 1, 2004•64 citations

Microfabricated Atomic Clocks at NIST

Svenja A. Knappe, Peter D. D. Schwindt, Vladislav P. Gerginov +5 more

This paper presents the latest progress in the development, fabrication, and characterization of microfabricated atomic frequency references at NIST. With volumes below 10 mm3 the physics packages contain the complete integrated assembly for probing the ground-state hyperfine splitting frequency of the alkali atoms by coherent population trapping (CPT). This technique allows for a simple and compact device containing a vertical-cavity surface-emitting laser (VCSEL), optics to shape the laser beam, a vapor cell containing the atoms, and a detector. We present an improved technique for microfabricating the miniature alkali vapor cells. When integrated into a CPT clock, a clear reduction of long-term frequency drifts is observed. This leads to a fractional frequency instability of less than 10-11 at one hour of integration, a more than one order of magnitude improvement over previous results. We identify the remaining sensitivities of the clock frequency to environmental influences and propose ways to reduce them.

•Dec 1, 2004•3 citations

A chip-scale atomic clock based on ^87Rb with improved frequency stability

Svenja A. Knappe, Peter D. D. Schwindt, Vishal Shah +4 more

We demonstrate a microfabricated atomic clock physics package based on coherent population trapping (CPT) on the D1 line of 87Rb atoms. The package occupies a volume of 12 mm3 and requires 195 mW of power to operate at an ambient temperature of 200 degrees C. Compared to a previous microfabricated clock exciting the D2 transition in Cs [1], this 87Rb clock shows significantly improved short- and long-term stability. The instability at short times is 4 x?10-11 / tau?/2 and the improvement over the Cs device is due mainly to an increase in resonance amplitude. At longer times (tau?> 50 s), the improvement results from the reduction of a slow drift to ?5 x 10-9 / day. The drift is most likely caused by a chemical reaction of nitrogen and barium inside the cell. When probing the atoms on the D1 line, spin-exchange collisions between Rb atoms and optical pumping appear to have increased importance compared to the D2 line.

Optics Express•Jan 1, 2005•238 citations
We demonstrate the critical subsystems of a compact atomic clock based on a microfabricated physics package. The clock components have a total volume below 10 cm3, a fractional frequency instability of 6 × 10−10/τ1/2, and consume 200 mW of power. The physics package is easily adapted to function as a magnetometer with sensitivity below 50 pT Hz−1/2 at 10 Hz.
Using the techniques of microelectromechanical systems, we are developing chip-scale atomic sensors based on laser excitation of alkali atoms. Recently, we demonstrated a magnetometer physics package based on coherent population trapping that had a sensitivity of 50 pT/Hzfrac12at 10 Hz, had a volume of 12 mm3, and used 195 mW of power as presented by Schwindt et al. (2004). To improve the sensitivity and reduce the power consumption of the magnetometer, we are evaluating other methods of interrogating the atoms for use in microfabricated devices. One of these methods uses frequency modulated nonlinear magneto-optical rotation (FM NMOR). We demonstrate that an FM NMOR magnetometer can be made to self-oscillate, offering simple construction and low power consumption
We have undertaken a development effort to produce a prototype chip-scale atomic clock (CSAC). The design goals include short-term stability, with a total power consumption of less than 30 mW and overall device volume <1 cubic cm. The stringent power requirement dominates the physics package architecture, necessarily dictating a small volume gaseous atomic ensemble interrogated by a low-power semiconductor laser. At PTTI 2002 and PTTI 2003, we reported on laboratory experiments that underlie the fundamental architecture of our CSAC, based on interrogation of the cesium D1 transition by the technique of coherent population trapping (CPT). In the past year, the development effort has shifted from fundamental research and feasibility investigation to engineering and prototype development. In this paper, we report on the design of a rugged and compact physics package that is expected to exceed the ultimate performance and power requirements of the CSAC.
This paper presents the latest progress in the development, fabrication, and characterization of microfabricated atomic frequency references at NIST. With volumes below 10 mm3 the physics packages contain the complete integrated assembly for probing the ground-state hyperfine splitting frequency of the alkali atoms by coherent population trapping (CPT). This technique allows for a simple and compact device containing a vertical-cavity surface-emitting laser (VCSEL), optics to shape the laser beam, a vapor cell containing the atoms, and a detector. We present an improved technique for microfabricating the miniature alkali vapor cells. When integrated into a CPT clock, a clear reduction of long-term frequency drifts is observed. This leads to a fractional frequency instability of less than 10-11 at one hour of integration, a more than one order of magnitude improvement over previous results. We identify the remaining sensitivities of the clock frequency to environmental influences and propose ways to reduce them.
We demonstrate a microfabricated atomic clock physics package based on coherent population trapping (CPT) on the D1 line of 87Rb atoms. The package occupies a volume of 12 mm3 and requires 195 mW of power to operate at an ambient temperature of 200 degrees C. Compared to a previous microfabricated clock exciting the D2 transition in Cs [1], this 87Rb clock shows significantly improved short- and long-term stability. The instability at short times is 4 x?10-11 / tau?/2 and the improvement over the Cs device is due mainly to an increase in resonance amplitude. At longer times (tau?> 50 s), the improvement results from the reduction of a slow drift to ?5 x 10-9 / day. The drift is most likely caused by a chemical reaction of nitrogen and barium inside the cell. When probing the atoms on the D1 line, spin-exchange collisions between Rb atoms and optical pumping appear to have increased importance compared to the D2 line.