Laser stabilizing to ytterbium clock transition with Rabi and Ramsey spectroscop

A cavity-stabilized 578 nm laser is used to probe the clock transition of ytterbium atoms trapped in optical lattice sites. We obtain a Fourier-limited 4.2-Hz-linewidth Rabi spectrum and a Ramsey spectrum with fringe linewidth of 3.3 Hz. Based on one of the spectra, the 578 nm laser light is frequen