Recent progress of neutral mercury lattice clock in SIOM

The optical lattice clock develops fast in recent years, and its stability and accuracy has already surpassed the microwave fountain clock and the optical clock based on ion trap. The mercury (Hg) lattice clock has the possibility to make a breakthrough in the limitation of blackbody radiation shift for strontium (Sr) and ytterbium (Yb) lattice clock, and reach the uncertainty in E-18 level at room temperature. For the purposes of laser cooling of mercury atoms and interrogating of the clock transition from S-1(0) state to P-3(0) state, a high-power cooling laser at 253.7 nm and an ultra-stable Hz-level linewidth laser at 265.6 nm are required, respectively. Here, we report our development of these laser sources for a neutral Hg lattice clock.