k.p-based multiband simulations of non-degenerate two-photon absorption in bulk GaAs
W.-R. Hannes, T. Meier, in: M. Betz, A.Y. Elezzabi (Eds.), Ultrafast Phenomena and Nanophotonics XXIV, 2020, p. 112780S.

Higher-order contributions and nonperturbative effects in the nondegenerate nonlinear optical absorption of semiconductors using a two-band model
W.-R. Hannes, T. Meier, Physical Review B 99 (2019).