A transportable optical lattice clock at the National Time Service Center

Kong De-Huan^{1, 2}, Wang Zhi-Hui³, Guo Feng^{1, 2}, Zhang Qiang^{1, 2}, Lu Xiao-Tong^{1, 2}, Wang Ye-Bing¹, Chang Hong^{1, 2, †}

(a) The measured spin-polarized spectra of the transitions from m_F = +9/2 to m_F = +9/2 and from m_F = –9/2 to m_F = –9/2. (b) Lorentz fitting (red solid) for the spin-polarized spectroscopy of the transition from m_F = +9/2 to m_F = +9/2 shows the linewidth of 4.8 Hz when the 698 nm interrogation time is 230 ms.