Precision spectroscopy with a single 40Ca+ ion in a Paul trap*
Guan Huaa),b), Huang Yaoa),b), Liu Pei-Lianga),b), Bian Wua),b),c), Shao Hua),b),c), Gao Ke-Lina),b)†
       
(a) A 1 Hz linewidth beatnote of the Ti:sapphire laser and the diode laser; (b) the beatnote stability of two locked lasers.