Drift-compensated Low-noise Frequency Synthesis Based on a cryoCSO for the KRISS-F1
Abstract
In this paper we report on the implementation and stability analysis of a drift-compensated frequency synthesizer from a cryogenic sapphire oscillator (CSO) designed for a Cs/Rb atomic fountain clock. The synthesizer has two microwave outputs of 7 GHz and 9 GHz for Rb and Cs atom interrogation, respectively. The short-term stability of these microwave signals, measured using an optical frequency comb locked to an ultra-stable laser, is better than at an averaging time of 1 s. We demonstrate that the short-term stability of the synthesizer is lower than the quantum projection noise limit of the Cs fountain clock, KRISS-F1(Cs) by measuring the short-term stability of the fountain with varying trapped atom number. The stability of the fountain at 1-s averaging time reaches at the highest atom number in the experiment when the synthesizer is used as an interrogation oscillator of the fountain. In order to compensate the frequency drift of the CSO, the output frequency of a waveform generator in the synthesis chain is ramped linearly. By doing this, the stability of the synthesizer at an average time of one hour reaches a level of which is measured with the fountain clock.
Cite
@article{arxiv.1610.02027,
title = {Drift-compensated Low-noise Frequency Synthesis Based on a cryoCSO for the KRISS-F1},
author = {Myoung-Sun Heo and Sang Eon Park and Won-Kyu Lee and Sang-Bum Lee and Hyun-Gue Hong and Taeg Yong Kwon and Chang Yong Park and Dai-Hyuk Yu and G. Santarelli and Ashby Hilton and Andre N. Luiten and John G. Hartnett},
journal= {arXiv preprint arXiv:1610.02027},
year = {2016}
}
Comments
8 pages, 6 figures