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Microfabricated Atomic Clocks at NIST



Svenja A. Knappe, P Schwindt, Vladislav Gerginov, V Shah, Leo W. Hollberg, John E. Kitching, Li-Anne Liew, John Moreland


In this paper we present the latest progress in the development, fabrication, and characterization of a microfabricated atomic frequency reference at NIST. With volumes below 10 mm3 the physics packages contain the complete integrated assembly for probing the hyperfine frequency of the alkali atoms by coherent population trapping (CPT). This technique allows for a simple and compact device containing a VCSEL, optics to shape the laser beam, a vapor cell containing the atoms, and a detector. We present an improved technique to microfabricate 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, an improvement of more than an order of magnitude over previous results. We identify the remaining sensitivities of the clock frequency to environmental influences and propose ways to reduce these.
Proceedings Title
Proc. PTTI
Conference Location
Washington, DC
Conference Title
Precise Time and Time Interval Planning and Applications Meeting


high-resolution, micro-optics, spectroscopy


Knappe, S. , Schwindt, P. , Gerginov, V. , Shah, V. , Hollberg, L. , Kitching, J. , Liew, L. and Moreland, J. (2004), Microfabricated Atomic Clocks at NIST, Proc. PTTI , Washington, DC, [online], (Accessed June 22, 2024)


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Created December 7, 2004, Updated February 17, 2017