Improving lattice-light-shift uncertainty of an ¹⁷¹Yb optical clock with optimized cooling and trapping lasers.

This article focuses on improving the frequency stability of lasers used in a ^171Yb optical lattice clock to reduce lattice-light-shift uncertainty, a key factor limiting clock accuracy. By locking a ring-cavity Ti:sapphire laser to an optical frequency comb referenced to a 578 nm ultra-stable laser, and transferring this stability to the 399 nm cooling laser via a 10 cm Fabry–Pérot cavity, the researchers enhanced atomic signal stability and achieved a lattice-light-shift uncertainty of 8.1 × 10^−18, an order of magnitude improvement over previous results. The magic frequency of the optical lattice was determined to be 394,798,266.6(1.3) MHz. The study employed self-comparison methods with controlled lattice detuning and trap depth modulation to evaluate the lattice-light-shift, highlighting the importance of precise laser frequency control for advancing optical lattice clock performance.