Laser-Induced Transitions between Triply Excited Hollow States

We present an ab initio calculation of the ${\mathrm{Li}}^{+}$ photoion yield in the presence of laser coupling between the triply excited ${2s}^2{2p}^2{P}^o$ and ${2s2p}^2{}_{}{}^2{}_{}{}^{}D_{}^e{}_{}{}^{}$ resonances in lithium, the first of which is assumed excited by synchrotron radiation from the ground state. The laser coupling between the triply excited states is shown to lead to a significant and readily measurable modification of the line profile which provides a unique probe of the dipole strength between highly correlated triply excited states.