Quantum interference shifts in laser spectroscopy with elliptical polarization

We investigate the quantum interference shifts between energetically close states, where the state structure is observed by laser spectroscopy. We report a compact and analytical expression that models the quantum interference induced shift for any admixture of circular polarization of the incident laser and angle of observation. An experimental scenario free of quantum interference can thus be predicted with this formula. Although, this study is exemplified here for muonic deuterium, it can be applied to any other laser spectroscopy measurement of $ns-n'p$ frequencies of a nonrelativistic atomic system, via a $ns\rightarrow n'p \rightarrow n"s$ scheme.