Precision measurement of hyperfine intervals in the D1 lines of atomic 7Li

Abstract

We report precise measurement of hyperfine intervals in the D1 lines of 7Li. Laser spectroscopy is performed in a collimated atomic beam and the laser-induced fluorescence is detected. The laser frequency determination is achieved by measuring the beat frequency between the spectroscopy laser and a reference laser which is frequency-stabilized to a molecular iodine transition and is calibrated by an optical frequency comb. We obtain a value of 91.892(7) MHz for the splitting in the 2P1/2 state, and 803.509(16) MHz for that in the 2S1/2 state. Our result resolves a discrepancy between former measurements and is consistent with most theoretical predictions. © 2013 IOP Publishing Ltd.