A phenomenological analysis and experimental observations of second-harmonic generation (SHG) in magnetic semiconductors with zinc blende crystal structure ¯43m in zero and nonzero magnetic fields are presented. A magnetic field reduces symmetry and gives rise to new SHG components. SHG transmission spectra were studied in Cd_1−xMn_xTe with x = 0.24, 0.35, and 0.40. At low temperatures a narrow SHG band at 1.98 eV in the vicinity of the fundamental bandgap was observed in a (110) sample with x = 0.24. The band disappears with a temperature increase when short-range magnetic ordering vanishes. Below the bandgap a SHG signal is found that varies strongly as a function of magnetic field. We relate this phenomenon to magnetic linear birefringence and the shift of the bandgap in a magnetic field.
© 2005 Optical Society of America
(160.6990) Materials : Transition-metal-doped materials
(190.4720) Nonlinear optics : Optical nonlinearities of condensed matter
(190.5970) Nonlinear optics : Semiconductor nonlinear optics including MQW
Victor V. Pavlov, Alexandra M. Kalashnikova, Roman V. Pisarev, Ingo Sänger, Dmitri R. Yakovlev, and Manfred Bayer, "Second-harmonic generation in the magnetic semiconductor (Cd, Mn)Te," J. Opt. Soc. Am. B 22, 168-175 (2005)