Spectroscopic studies of alkali atom-rare gas systems

We describe a series of measurements of absorption and laser induced fluorescence on cells that contained cesium and rubidium and a rare gas: He, Ar, Kr, or Xe. These studies showed strong blue wing absorption to the short wavelength side of the alkali atom D2 lines due to collisionally formed Cs- or Rb-rare gas excimers. We also have observed an efficient two photon excitation of higher lying states in Cs and Rb that produces both intense blue emission and IR atomic emission in the 1.3 to 3.8 μm spectral region.