Role of the relative phase and intensity ratio in electron-ion recombination assisted by a bicircular laser field

Abstract

S-matrix theory is used in order to analyze the energy spectra of electron-ion radiative recombination assisted by a bicircular (two-component circularly polarized) laser field. The analysis includes the cases of corotating and counterrotating laser-field components. The scattering effects are also included by applying the second Born approximation in the expansion of the S-matrix element. We have investigated the sensitivity of the emitted photon energy spectra to the relative phase and intensity ratio of the laser-field components. The obtained energy spectra show the plateau-like oscillatory structures with abrupt cutoffs. Positions of these cutoffs in the energy spectra are confirmed by a classical analysis. Scattering effects may be observed in the calculated energy spectra not only in the case of counterrotating, but also in the case of corotating laser-field components. This is different from the process of above-threshold ionization/detachment by a bicircular laser field, where the scattering effects in the photoelectron energy spectra may be observed only in the case of counterrotating laser-field components.