  We consider the two-photon ionization of Hydrogen-like atoms. We find an
approximate expression of the long-range phase based on an asymptotic expansion
of the continuum eigenfunctions within the Wentzel-Kramers-Brillouin
approximation. Combined with commonly used perturbative approaches, the
resulting analytic formalism can treat, at the same time, the two-photon
propensity rules, the anisotropy in the continuum-continuum photoionization
time delay and the soft-photon regime.
