title: Magnetic-field-induced second-harmonic generation in semiconductor GaAs.
abstract: We show that application of a magnetic field induces optical second-harmonic generation (SHG) in GaAs. This phenomenon arises from field-induced symmetry breaking causing new optical nonlinearities. A series of narrow SHG lines is observed in the spectral range from 1.52 to 1.77 eV that we attribute to Landau-level quantization of the band energy spectrum. The rotational anisotropy of the SHG signal distinctly differs from that of the electric-dipole approximation. Model calculations reveal that nonlinear magneto-optical spatial dispersion that comes together with the electric-dipole term is the dominant mechanism for this nonlinearity.
authors.affiliation: A. F. Ioffe Physical-Technical Institute, The Russian Academy of Sciences, 194021 St. Petersburg, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Pavlov
authors.forename: A M
authors.initials: AM
authors.lastname: Kalashnikova
authors.forename: R V
authors.initials: RV
authors.lastname: Pisarev
authors.forename: I
authors.initials: I
authors.lastname: Sänger
authors.forename: D R
authors.initials: DR
authors.lastname: Yakovlev
authors.forename: M
authors.initials: M
authors.lastname: Bayer