Precise two-photon spectroscopy ofE←X*intervals inH2

Abstract

We have precisely measured the vacuum ultraviolet intervals between several rotationally and vibrationally excited levels of ground-state ${\mathrm{H}}_2$ and the $E$, $F{{}_{}{}^1{}_{}{}^{}\Sigma _g^{}{}_{}{}^{}}^{+}$ state. An accuracy of 0.01 ${\mathrm{cm}}^{-1\mathrm{}}$, an order of magnitude better than previously available, is achieved using a pulsed discharge source in conjunction with a pulse amplified cw laser system. These measurements also serve as a calibration for numerous other excited states connected by optical intervals to the $E$, $F$ state.