Development of an Yb optical lattice clock at KRISS

An Yb optical lattice clock is under development at KRISS. Yb atoms were trapped in an optical lattice and further optimization is underway. Linewidth of the probe laser at 578 nm developed by sum frequency generation (SFG) method was reduced to less than 100 Hz. We also developed an optical frequency synthesizer (OFS) with the carrier-envelope-offset frequency locked to 0 Hz using the “direct locking method”.