The oscillator strength of the (6s6p${)\mathrm{}}^3$$P_1$-(6s7s${)\mathrm{}}^1$$S_0$ transition and the lifetime of the (6s7s${)\mathrm{}}^1$$S_0$ state in ${}_{}{}^{174}{}_{}{}^{}\mathrm{Yb}$ have been measured to be (8.0±1.6)×${10}^{\mathrm{-}4}$ and 45.8±1.0 nsec, respectively. The former value was obtained by use of coherent optical techniques (optical nutation and ac Stark splitting), while the latter was obtained by monitoring cascade fluorescence following pulsed excitation.

• Received 15 August 1986

DOI:https://doi.org/10.1103/PhysRevA.35.619