Abstract：The optical clock-transition spectrum of cold 171Yb atoms confined in the one-dimensional optical lattice is optimized and the frequency stability of the clock laser is evaluated with its frequency locked to the atomic transition. In the Lamb-Dicke regime and well-resolved sideband regime, a typical clock-transition spectrum with a carrier-sideband structure is observed. By minimizing the power broadening effect and compensating the stray magnetic field, the spectral linewidth decreases continuously to the Fourier limit which is determined by the interrogation time. The carrier linewidth is narrowed to about 16 Hz for a 60 ms interrogation time. By increasing the interrogation time to 150 ms, the linewidth is further reduced to 6 Hz. On basis of these optimization measures, the clock laser is locked to the atomic transition via the feedback loop. The instability of the clock frequency reaches about 1×10－16 at an averaging time of 1 000 s.
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