The “Trapped State” of a Trapped Ion—Line Shifts and Shape

Abstract

The fluorescence of a single r.f.-trapped and cooled Ba+ ion, induced by the light of two lasers, shows a null at the S1/2-D3/2 resonance of the frequency difference. We have measured the Zeeman effect and power broadening of this "dark line", and also the shift of the associated "bright" line, which is related to the Raman light shift. A 75 kHz wide dark line was observed. Such a resonance might be used to control a 147 THz standard frequency free of systematic shifts in excess of 10-15.