Biomedical subjects

Pierre Lemonde

Publications and source records attributed to Pierre Lemonde.

2 recordsLinked to original sources

PubMed2006

Accurate optical lattice clock with 87Sr atoms.

We report a frequency measurement of the 1S0-3P0 transition of 87Sr atoms in an optical lattice clock. The frequency is determined to be 429 228 004 229 879(5) Hz with a fractional uncertainty that is comparable to state-of-the-art optical clocks with neutral atoms in free fall. The two previous measurements of this transition were found to disagree by about 2 x 10(-13), i.e., almost 4 times the combined error bar and 4 to 5 orders of magnitude larger than the claimed ultimate accuracy of this new type of clocks. Our measurement is in agreement with one of these two values and essentially resolves this discrepancy.

Journal Article↗

PubMed2006

Hyperpolarizability effects in a Sr optical lattice clock.

We report the observation of a higher-order frequency shift due to the trapping field in a (87)Sr optical lattice clock. We show that, at the magic wavelength of the lattice, where the first-order term cancels, the higher-order shift will not constitute a limitation to the fractional accuracy of the clock at a level of 10(-18). This result is achieved by operating the clock at very high trapping intensity up to 400 kW/cm(2) and by a specific study of the effect of the two two-photon transitions near the magic wavelength.

Journal Article↗