Magnetization-induced optical nonlinearity in ferromagnetic GaMnAs

We report the observation of a coherent nonlinear signal in pump-probe experiments on a ferromagnetic GaMnAs. The coherent signal, which is originating due to coherent interaction between pump and probe beams, depends on the polarization configuration of each beam and follows the sample magnetization as it changes with the applied magnetic field and/or the sample temperature. (c) 2007 American Institute of Physics.