SINGLE, TRAPPED SR+ ATOM - LASER COOLING AND QUANTUM JUMPS BY MEANS OF THE 4D2D5/2-5S2S1/2 TRANSITION

A single Sr+ atom was confined in a radio-frequency quadrupole trap and laser cooled with resonant laser light. Examination of the transition Doppler profile indicated an ion kinetic temperature of less than 500 mK. Quantum jumps into and out of the metastable 4d 2D5/2 level were observed by laser excitation on the electric-quadrupole-allowed transition from the ground state at 674 nm. The dark and bright periods in the strong fluorescence showed variations owing to the applied driving field on the electric-quadrupole transition. These results provide an improved determination ofτ = 372 ± 25 msec for the natural metastable-state lifetime. © 1990 Optical Society of America.