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Advances in Chip-Scale Atomic Frequency References at NIST



Svenja A. Knappe, V Shah, Alan Brannon, Vladislav Gerginov, Hugh Robinson, Z Popovic, Leo W. Hollberg, John E. Kitching


We present new advances in the development of chip-scale atomic frequency references. Coherent population trapping (CPT) resonances usually exhibit contrasts below 10 %, when interrogated with frequency modulated lasers. A relatively simple way to increase the resonance contrast to nearly 100 % will be discussed. It is based on the generation of an additional light field through a non-linear 4-wave mixing interaction in the atomic vapor 1. A similar method can also be used to create a beat signal at the CPT resonance frequency that can injection-lock a low-power microwave oscillator at 3.4 GHz directly to the atomic resonance2. This could lead to chip-scale atomic clocks (CSACs) with improved performance. A miniature microfabricated saturated absorption spectroscopy setup will be introduced3. It produces a signal for locking a laser frequency to optical transitions in alkali atoms. The Rb absorption spectra are comparable to signals obtained with standard table-top setups, although the rubidium vapor cell has an interior volume of only 1 mm3 and the volume of the entire spectrometer is around 0.1 cm3.
Proceedings Title
Proc. SPIE Conf.
Conference Dates
August 26-30, 2007
Conference Location
San Diego, CA


chip-scale atomic clock, CSAC, frequency reference, microfabrication, saturation spectroscopy


Knappe, S. , Shah, V. , Brannon, A. , Gerginov, V. , Robinson, H. , Popovic, Z. , Hollberg, L. and Kitching, J. (2007), Advances in Chip-Scale Atomic Frequency References at NIST, Proc. SPIE Conf., San Diego, CA, [online], (Accessed June 22, 2024)


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Created September 12, 2007, Updated February 17, 2017