Realization of Closed-Loop Operation of Optical Lattice Clock Based on 171Yb

We report the realization of closed-loop operation of an optical lattice clock based on Yb-171 atoms. We interrogate the 1S(0) -> P-3(0) clock transition using single Rabi pulses of 578nm laser light. The two pi-transitions from m(F) = +/- 1/2 ground states are alternatively interrogated, and the clock laser frequency is locked to the center of the two resonances. The in-loop error signal stability of the clock reaches 3 x 10(-17) for an average time of 3500 s. We also perform interleaved operations of the clock with two independent servo loops, and the fractional frequency difference averages down to 2 x 10(-16) in 7200 s.