Floquet calculations for H2+ photoionization

Abstract

We present results of calculations of rates for ionization of the lowest electronic state of the H2+ ion by a continuous-wave laser field. We solve the coupled-channel Floquet equations in both length and velocity gauges using a pseudospectral method. We employ a complex absorbing potential to obtain Siegert-type solutions resulting in resonance positions and widths. We calculate generalized cross sections for one-, two-, and three-photon ionizations for various internuclear separations of the ion with intensity of I = 1.76 × 1012 W/cm2. This is the first time the Floquet technique combined with the complex absorbing potential has been employed for photoionization cross sections of the ion. We report on ionization rates of the ion for different internuclear distances with intensity of I = 5 × 1013 W/cm2. We also present two-photon ionization cross section for different internuclear distances with intensities of I = 1.76 × 1013 and 1.76 × 1014 W/cm2. We compare our findings from calculations carried out in both gauges with those of previous calculations.