A delayed-coincidence technique has been used to measure the lifetime of the
5d6p1F3 state of atomic barium. An intermediate,
6s5d1D2 metastable state of barium atoms in an atomic beam was populated by electron bombardment, and a pulsed cw laser was employed to excite atoms from the metastable state to the
5d6p1F3 state. A time-to-amplitude convertor was used to measure the time distribution of the fluorescent light. The value obtained for the lifetime was (44.5\ifmmode\pm\else\textpm\fi{}1.8) nsec.
We have measured the lifetime of the
3P1 metastable state of Mg and obtained a value of 2.2 \ifmmode\pm\else\textpm\fi{} 0.2 msec. The level was excited with a dye laser tuned to the intercombination line ($3s3p^{3}P_{1}\ensuremath{\leftrightarrow}3{s}^{2}^{1}S_{0}$). In addition to the
3P1 state, the
3P2 and
3P0 levels were populated by mixing collisions owing to the presence of an inert buffer gas. The populations of all three metastable levels were monitored as a function of time by observing the absorption of Mg resonance radiation ($^{3}P_{0,1,2}\ensuremath{\rightarrow}^{3}S_{1}$) out of each level. The mixing time was short compared to the
3P1 lifetime, so that the populations of the three metastable levels were in thermal equilibrium with each other. This produced an apparent lengthening of the
3P1 lifetime, which would introduce a large systematic error if the degree of mixing were not known. Cenventionally, one observes the fluorescence from the excited levels to obtain their lifetimes. Because the lifetimes of the
3P2 and
3P0 states are too long, fluorescence from these states cannot be observed, and the observation of fluorescence from the
3P1 state alone provides insufficient information to determine its lifetime.
Abstract We report the measurement of the metastable-state lifetime of erbium ions doped in a fiber. We apply the pump–probe technique with a wavelength-tunable laser array. This technique allows us to measure the lifetime through delayed absorption in the fiber propagation directions. By tuning the wavelength of the pump–probe pulse pairs to a low absorption wavelength, the lifetime of the metastable state is successfully measured in a 5-m-long fiber. The lifetime is determined to be 10.0 ms, which agrees well with previously reported values.