Laser spectroscopy of the6dσstates of CsAr and CsKr

In this work a more sensitive, multiphoton technique has been introduced for the study of the electronic transitions of alkali-metal-inert-gas excimers. In situ detection of the ionization resulting from multiphoton excitation through resonant excimer states has been accomplished through the inclusion of a space-charge-limited diode in an absorption cell. By using a pulsed tunable dye laser with a linewidth of 0.01 nm, absorption signals from CsAr and CsKr excimers at levels of ${10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$ have been recorded with signal-to-noise ratios of 40. Relatively low cesium vapor pressures of 0.12 Torr and inert-gas densities ranging from 0.6 to 0.9 amagat were used to minimize interference from overlapping dimer bands. Dispersion curves of the photoionization of CsAr and CsKr over the 430- to 460-nm wavelength range showed single-photon resonances corresponding to the parts of the $6s\sigma \to 6d\sigma$ absorption bands leading to the production of bound $6d{\sigma }_{\frac{1}{2}}$ molecules. The experimental results obtained in this work correlated reasonably well with the available theoretical potential curves.