Different polarization of theAΠ2andCΠ2state wave functions in CaF observed by visible and uv Stark spectroscopy

With the application of high-resolution laser spectroscopy to a molecular beam of CaF the Stark effect of individual rotational lines of the $A{}_{}{}^2{}_{}{}^{}\Pi -X{}_{}{}^2{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$ (603.7 nm) and $C{}_{}{}^2{}_{}{}^{}\Pi -X{}_{}{}^2{}_{}{}^{}\Sigma _{}^{+}{}_{}{}^{}$ (330.8 nm) systems was measured. The electric dipole moments of the $A{}_{}{}^2{}_{}{}^{}\Pi$ and $C{}_{}{}^2{}_{}{}^{}\Pi$ states were determined as $\mu \left(A{}_{}{}^2{}_{}{}^{}\Pi \right)=2.45\mathrm{}\left(6\right)\mathrm{}$ D and $\mu \left(C{}_{}{}^2{}_{}{}^{}\Pi \right)=9.24\mathrm{}\left(17\right)\mathrm{}$ D. These extremely different values can be explained by the different polarization of the unpaired, ${\mathrm{Ca}}^{+}$-centered electron in the two electronically excited states. The main contributions to the two corresponding orbitals derive from the same ${\mathrm{Ca}}^{+}$ wave functions.