Precision measurements of the lifetime of a single trapped ion with a nonlinear electro-optic switch

A time-correlated single-photon counting method is used to measure the spontaneous emission lifetime of a single trapped barium ion, yielding a standard deviation of 0.5% for 8 min of integration time. The statistical power of this one-atom technique is comparable with that of other methods that use a macroscopic sample, but the technique has potentially lower systematic errors. The method depends on the use of an electro-optic phase modulator as an Nth-order nonlinear switch, which improves the response time by a factor of N and the on–off ratio by the Nth power. © 1994 Optical Society of America.