High resolution laser spectroscopy of Cs2. II. Doppler-free polarization spectroscopy of the CuX 1Σ+g system

Abstract
More than 2000 completely resolved rotational lines in the C 1Πu(1u)←X 1Σ+g(0+g) band‐system and 200 lines in the D 1Σu(0+u)←X 1Σ+g system of Cs2 have been accurately measured with the techniques of Doppler‐free polarization spectroscopy and optical–optical double resonance (OODR). The wave numbers of these lines were determined within 10−3 cm−1 using a traveling Michelson interferometer and a 120 cm confocal Fabray–Perot interferometer. The OODR technique allows the unambiguous assignment of even perturbed lines, and enables us to find different perturbations in the upper C 1Πu(1u) state. A thorough analysis of the measured data, including laser induced fluorescence lines from higher electronic states into high lying vibrational levels of the electronic ground state, yields molecular constants, potential energy curves, and Franck–Condon factors.