Absolute frequency measurement of the 6s6p 3P0 → 5d6s 3D1 transition based on ultracold ytterbium atoms

摘要

The 1389-nm laser is used as a repumping laser in the 171Yb optical lattice clock, which corresponds to the 6s6p 3P0 & RARR; 5d6s 3D1 transitions. To our knowledge, there is no report on the absolute frequencies for this repumping transition yet. We excite the hyperfine structure transitions with a 1389-nm scannable laser, which is stabilized on an absolute frequency-stabilized optical frequency comb, and obtain the transition spectra. The min-imum spectral linewidth is around 705 kHz, which is approximately 1.5 times greater than the natural linewidth of 484 kHz. Based on evaluating the systematic frequency shifts precisely and referencing the frequency measurement results on the secondary representation of the International System of Units second, we are the first to report the direct measurement of the absolute frequencies for 6s6p 3P0 (F= 1/2)& RARR; 5d6s 3D1 (F= 1/2, 3/2) transitions are 215 875 746.15 & PLUSMN; (0.21)stat & PLUSMN; (0.06)sys MHz and 215 872 697.14 & PLUSMN; (0.11)stat & PLUSMN; (0.06)sys MHz, respectively. In addition, the hyperfine splitting and magnetic dipole coefficient A of the 5d6s 3D1 state is determined as 3049.01(26) MHz and -2032.67(17) MHz, which is more accurate than the previous measurements by an order of magnitude.

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