Optical-clock local-oscillator stabilization scheme

Stabilization of a laser to an optical-clock transition has been demonstrated using Ramsey's phase-modulation technique. The technique was implemented using a 674 nm laser and a component of the 5 s {sup 2}S{sub 1/2}{yields}4d {sup 2}D{sub 5/2} optical clock transition in a single {sup 88}Sr{sup +} ion. The lock performance observed was consistent with the short-term stability of the local oscillator. Compared with existing frequency-modulation stabilization schemes, this technique offers advantages for use in single-ion optical clocks through its possible increased resolution and the ability to conveniently compensate known systematic shifts.