The two-photon absorption (TPA) cross section in zinc-blende-structure semiconductors has been analyzed, both analytically and numerically. The warping of the valence band is shown to result in a dependence of the TPA on the orientation of the polarization plane of the light with respect to the crystal axes, i.e., in a linear dichroism. In InSb and GaAs, the relative differences in the TPA cross sections for light polarized along 〈100〉 and 〈111〉 axes, depending on the light wavelength, are 0.02–0.05 and 0.13–0.20, respectively. The linear-circular dichroism of TPA, even in narrow-band-gap semiconductors, is noticeably influenced by the presence of a split-off valence subband.

• Received 13 May 1991

DOI:https://doi.org/10.1103/PhysRevB.45.5926