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Long-term Frequency Stability of Chip-Scale Atomic Clocks

Published

Author(s)

Vladislav Gerginov, Svenja A. Knappe, V Shah, P Schwindt, Leo W. Hollberg, John E. Kitching

Abstract

We present an evaluation of the long-term frequency instability and environmental sensitivity of a chip-scale atomic clock based on coherent population trapping (CPT), particularly as affected by the light source subassembly. The long-term frequency stability of this type of device can be dramatically improved by judicious choice of operating parameters of the light source subassembly. We find that the clock frequency is influenced by the laser injection current, laser temperature and RF modulation index. The sensitivity of the clock frequency to changes in laser injection current or substrate temperature can be significantly reduced through adjustment of the RF modulation index. This makes the requirements imposed on the laser temperature stabilization, in order to achieve a given frequency stability, less severe. The clock frequency instability due to variations in local oscillator power is shown to be reduced through the choice of an appropriate light intensity inside the cell. While this work is intended to improve the performance of a chip-scale device, it is applicable to similar compact atomic clocks based on coherent population trapping.
Citation
Long-term Frequency Stability of Chip-Scale Atomic Clocks

Keywords

atomic clock, chip scale, coherent population trapping, frequency stability, magnetometer, servo

Citation

Gerginov, V. , Knappe, S. , Shah, V. , Schwindt, P. , Hollberg, L. and Kitching, J. (2006), Long-term Frequency Stability of Chip-Scale Atomic Clocks, Long-term Frequency Stability of Chip-Scale Atomic Clocks, [online], http://tf.nist.gov/timefreq/ofm/smallclock/LongTermStability.htm (Accessed March 4, 2024)
Created January 26, 2006, Updated February 17, 2017