Abstract

The lack of high resolution investigations of oxygen is caused by the fact that, like for many other light atoms, the resonance lines are in the vacuum ultraviolet (VUV) region, where tunable radiation of high intensity and spectral purity is hard to produce. The ground state fine structure splittings are the only high accuracy data available for oxygen since they could be directly measured at far infrared frequencies [1,2] where Doppler effect does not affect significantly the experimental determinations. In spite of the extreme difficulty, the very low probability transitions in the red from the ground state were detected by cw laser intracavity configuration [3] but with no high resolution.

© 1988 Optical Society of America