Simple, elegant technique for single isotope detection

Summary form only given. Barium (Ba) is a versatile atom for basic quantum optical measurements because it possesses multiple transitions at conveniently accessible wavelengths which allow the creation of a variety of useful systems. This atom has been used as a three-level /spl Lambda/, cascade, and V system for driven atom and lasing without inversion experiments. Other work relied on the (6s/sup 2/)/sup 1/S/sub 0/-(6s6p)/sup 1/P/sub 1/ 553.5 nm transition as a two-level system for cavity quantum electrodynamics, two-photon laser, and single-atom laser experiments. However, these observations, which utilize natural Ba, are complicated by the presence of multiple isotopes with small frequency shifts. These isotopes introduce additional features and under certain conditions mask small structures, making interpretation of the results non-trivial.