Hyperfine Structure in the Visible Molecular-Iodine Absorption Spectrum

Abstract

The observed hyperfine structure in the visible iodine absorption spectrum can be explained as a combination of a nuclear electric quadrupole interaction in both the ground and excited electronic states with a difference in coupling constants $(eQ{q}^{\ensuremath{'}}\ensuremath{-}eQ{q}^{\ensuremath{'}\ensuremath{'}})=\ensuremath{-}958\ifmmode\pm\else\textpm\fi{}15$ MHz (0.032 ${\mathrm{cm}}^{\ensuremath{-}1}$) and a magnetic hyperfine interaction in the excited state with a coupling constant of 500\ifmmode\pm\else\textpm\fi{}100 MHz (0.017 ${\mathrm{cm}}^{\ensuremath{-}1}$).