Title :
All-optical atomic clocks
Author :
Drullinger, R.E. ; Udem, Th ; Diddams, Scott A. ; Vogel, K.R. ; Oates, C.W. ; Curtis, E.A. ; Lee, W.D. ; Itano, K.M. ; Hollberg, L. ; Bergquist, J.C.
Author_Institution :
Nat. Inst. of Stand. & Technol., Boulder, CO, USA
fDate :
6/23/1905 12:00:00 AM
Abstract :
We have developed two all-optical clocks in which the RF output is generated directly from the optical process within the clockwork. The frequency comb created by a femtosecond mode-locked laser and a microstructure fiber is used to phase-coherently measure the frequencies of both the Hg+ and Ca optical frequency standards with respect to the SI second as realized at NIST. We find the transition frequencies to befHg=1064721609899143(10) Hz and fCa =455986240494158(26) Hz, respectively. This work begins to reveal the high stability and potential for accuracy of optical atomic clocks. Furthermore, when combined with previous measurements, we find no time variations of these atomic frequencies within the uncertainties of 1|(∂fHg/∂t)/fHg| =2×10-14 yr-1 and |(∂fCa/∂t)/fCa| =8×10-14 yr-1
Keywords :
atomic clocks; frequency standards; laser frequency stability; laser mode locking; optical harmonic generation; Ca; Hg; NIST SI second; RF output; all-optical atomic clocks; dye laser; femtosecond mode-locked laser; frequency comb; frequency-doubled output; harmonic frequency chain; high stability; metastable state; microstructure fiber; optical comb; optical frequency standards; phase-coherent measurement; quadrupole resonance; subhertz linewidth; transition frequencies; Atom optics; Atomic clocks; Atomic measurements; Fiber lasers; Frequency measurement; Laser mode locking; Laser transitions; Mercury (metals); Radio frequency; Ultrafast optics;
Conference_Titel :
Frequency Control Symposium and PDA Exhibition, 2001. Proceedings of the 2001 IEEE International
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-7028-7
DOI :
10.1109/FREQ.2001.956162
