Doppler-Free Spectroscopy of the S-1(0)-P-3(0) Optical Clock Transition in Laser-Cooled Fermionic Isotopes of Neutral Mercury

LNE-SYRTE, Observatoire de Paris, 75014 Paris, France.
Physical Review Letters (Impact Factor: 7.73). 11/2008; 101(18):183004. DOI: 10.1103/PhysRevLett.101.183004
Source: PubMed

ABSTRACT We report direct laser spectroscopy of the 1S0-3P0 transition at 265.6 nm in fermionic isotopes of neutral mercury in a magneto-optical trap. Measurements of the frequency against the LNE-SYRTE primary reference using an optical frequency comb yield 1 128 575 290 808.4+/-5.6 kHz in 199Hg and 1 128 569 561 139.6+/-5.3 kHz in 201Hg. The uncertainty, allowed by the observation of the Doppler-free recoil doublet, is 4 orders of magnitude lower than previous indirect determinations. Mercury is a promising candidate for future optical lattice clocks due to its low sensitivity to blackbody radiation.

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