OPTICAL PROBING OF COLD TRAPPED ATOMS

Transitions between excited states of laser-cooled and laser-trapped r ubidium and cesium atoms are probed by use of fiber and diode lasers. High-resolution Doppler-free spectra are detected by observation of th e absorption and fluorescence of light from the intermediate level of two-step cascade systems. The optical double-resonance spectra show Au tler-Townes splitting in the weak probe limit and more complicated spe ctra for a strongly coupled three-level system.