Publication Date:
2001-07-14
Description:
Microwave atomic clocks have been the de facto standards for precision time and frequency metrology over the past 50 years, finding widespread use in basic scientific studies, communications, and navigation. However, with its higher operating frequency, an atomic clock based on an optical transition can be much more stable. We demonstrate an all-optical atomic clock referenced to the 1.064-petahertz transition of a single trapped 199Hg+ ion. A clockwork based on a mode-locked femtosecond laser provides output pulses at a 1-gigahertz rate that are phase-coherently locked to the optical frequency. By comparison to a laser-cooled calcium optical standard, an upper limit for the fractional frequency instability of 7 x 10(-15) is measured in 1 second of averaging-a value substantially better than that of the world's best microwave atomic clocks.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Diddams, S A -- Udem, T -- Bergquist, J C -- Curtis, E A -- Drullinger, R E -- Hollberg, L -- Itano, W M -- Lee, W D -- Oates, C W -- Vogel, K R -- Wineland, D J -- New York, N.Y. -- Science. 2001 Aug 3;293(5531):825-8. Epub 2001 Jul 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Time and Frequency Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA. sdiddams@boulder.nist.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11452082" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
