Frequency measurement of 6s6p 3P0,2−6s7s 3S1 transitions in ultracold 171Yb atoms referenced to local optical clock

Abstract

We experimentally determine the absolute frequencies and hyperfine splittings of the 6s6p 3P0,2 − 6s7s 3S1 transitions of ultracold 171Yb atoms in an optical lattice. A frequency comb referenced to an ultrastable optical cavity is used to measure the electric-dipole transition frequencies. With the normalized shelving detection technique, about 12 MHz and 10 MHz linewidth of atomic spectra are obtained, respectively, which is some greater than the natural linewidth of 1.5 MHz and 5.9 MHz and is limited by the broadening from the probe and lattice light. By reference to our 171Yb 6 s2 1S0 − 6s6p 3P0 clock, the absolute frequencies are found to be 461861338.03 (0.21) MHz and 461871596.07 (0.31) MHz for the 6s6p 3P0 − 6s7s 3S1 (F = 1/2 and F = 3/2) transitions, which are more accurate than the previous measurement by one order of magnitude. For the 6s6p 3P2 (F = 3/2 and F = 5/2) − 6s7s 3S1 (F = 1/2 and F = 3/2) transitions, the measured frequencies are 389257019.71 (0.65) MHz, 389267277.10 (0.37) MHz and 389260569.95 (0.89) MHz, respectively, which are the first measurements to our knowledge. Furthermore, the hyperfine constants for the 6s6p 3P2 and 6s7s 3S1 states are determined to be 2682.86(0.38) MHz and 6838.69(0.25) MHz, both of which agree well with other recent experimental results.

Keywords

• Cold ytterbium atoms
• Optical clocks
• Absolute frequency measurement
• Hyperfine constants