Abstract

Precise measurements of deep ultraviolet transitions in atoms and molecules pose a special challenge to the spectroscopist because of the high order of nonlinearity required to measure a transition below 100 nm starting with a visible laser as the light source. This challenge is particularly compelling in the case of the hydrogen molecule, where precise calculations of the ionization potential with uncertainties of a few parts in 10⁷ have gone largely untested because of the difficulty of measuring the 100 000 cm⁻¹ interval from the ground state to the nearest excited states.

© 1990 Optical Society of America