Investigation of the 4f ¹⁴6s^{2 1}S₀−4f ¹³5d6s² (J = 2) clock transition at 431 nm of ¹⁷¹Yb atoms trapped in an optical lattice

With the aid of an optical frequency divider based on an optical frequency comb, the frequency of a laser at 431 nm is divided from a cavity-stabilized laser at 578 nm. Using the frequency-stabilized 431 nm laser, we observe a 2.5 kHz linewidth 4f ¹⁴6s^{2 1}S₀−4f ¹³5d6s² (J = 2) transition of ¹⁷¹Yb atoms trapped in an optical lattice. By measuring the lattice-induced frequency shift, we determine the magic wavelength of the optical lattice for the 431 nm transition to be 797.97(20) nm. The frequency of the 431 nm transition is measured to be 695 171 054 856.9(1.1) kHz by referencing to the ¹S₀−³P₀ transition at 578 nm of Yb atoms.