  We report on a quantitative experimental determination of the
three-dimensional magnetization vector trajectory in GaMnAs by means of the
static and time-resolved pump-and-probe magneto-optical measurements. The
experiments are performed in a normal incidence geometry and the time evolution
of the magnetization vector is obtained without any numerical modeling of
magnetization dynamics. Our experimental method utilizes different polarization
dependences of the polar Kerr effect and magnetic linear dichroism to
disentangle the pump-induced out-of-plane and in-plane motions of
magnetization, respectively. We demonstrate that the method is sensitive enough
to allow for the determination of small angle excitations of the magnetization
in GaMnAs. The method is readily applicable to other magnetic materials with
sufficiently strong circular and linear magneto-optical effects.
