Strong-field induced optical anisotropy in semiconductors with cubic structure: theory

Abstract A mechanism pertaining to an anomalous optical anisotropy under a strong field in semiconductors having cubic structure is proposed. The valence-conduction band transitions of valence electrons located around atomic bonds re-distribute electrons between bands and, consequently, produce symmetry defects in local electronic density. The optical anisotropy is due to these symmetry defects, which are the sources for localized and non-compensated dipole moments randomly distributed within the crystal. The quantum time-dependent probability amplitude method, combined with classical electrodynamics, demonstrate that the non-compensated dipole moments destroy the optical isotropy of a crystal. To compare the scheme with an experiment, the theory is applied to G a A s single crystal. Within a strong-field IR regime, the predicted four-fold symmetry of optical anisotropy, along with its amplitude, correlate well with an experiment.