The filamentation instability of electromagnetic waves in semiconductors in a uniform magnetic field is investigated. The nonlinear responses of the medium, including the nonparabolic dispersion of the conduction carriers as well as the second-order density and magnetic field perturbations that are created by the radiation pressure, are taken into account. The spatial amplification rate and threshold field associated with the filamentation instability are presented. The relevance of our work to electromagnetic-wave propagation in a sample of narrow-band-gap semiconductors is pointed out.

• Received 30 January 1989

DOI:https://doi.org/10.1103/PhysRevB.39.12941