Spectroscopy and frequency measurement of the $^{87}$Sr clock transition by laser linewidth transfer using an optical frequency comb

摘要

We perform spectroscopic observations of the 698-nm clock transition in$^{87}$Sr confined in an optical lattice using a laser linewidth transfertechnique. A narrow-linewidth laser interrogating the clock transition isprepared by transferring the linewidth of a master laser (1064 nm) to that of aslave laser (698 nm) with a high-speed controllable fiber-based frequency comb.The Fourier-limited spectrum is observed for an 80-ms interrogating pulse. Wedetermine that the absolute frequency of the 5s$^{2}$ $^{1}$S$_{0}$ - 5s5p$^{3}$P$_{0}$ clock transition in $^{87}$Sr is 429 228 004 229 872.0 (1.6) Hzreferenced to the SI second.