Development of an ytterbium optical lattice clock at KRISS

This paper describes the current status of an ytterbium lattice clock under development at KRISS. After the success of 399 nm magneto-optical-trap (MOT) at a temperature 1 mK, we constructed the 2^nd stage cooling laser system at a wavelength of 556 nm to cool atoms further down to several muK. We are also developing an ultra-narrow linewidth laser at a wavelength of 578 nm to probe the clock transition by doubling the frequency output of a commercial 1156 nm ECDL. Efforts to reduce the linewidth are under way.