Two-photon-absorption spectra of Si, ZnSe, and GaAs are evaluated in a wide photon-energy range by using ab initio full-band-structure and microscopic-nonlinear-susceptibility calculations. It is shown that Si and ZnSe have abundant spectral structures originating from the transitions at both the center and boundary of the Brillouin zone, being in good agreement with recent experimental results. The calculated spectra are analyzed by comparing with those of one-photon absorption and the scaling formula.

• Received 14 December 1993

DOI:https://doi.org/10.1103/PhysRevB.49.5737