Time-resolved four-wave-mixing signal in thick bulk GaAs

Summary form only given. Time-integrated (TI) and time-resolved (TR) four-wave-mixing (FWM) techniques have been employed successfully to study the relaxation dynamics of coherent excited states in semiconductors and semiconductor quantum wells. A large number of experimental and theoretical studies on FWM have been mainly focused on the resonant FWM signals in thin semiconductors with thicknesses of less than 1 /spl mu/m so far. If the sample is optically thick, however, the input pulse is severely distorted and the propagation effect of the generated FWM signal becomes more and more important and complicated. We performed the TI- and TR-FWM experiments and measured the pulse shape of the transmitted probe beam in the presence of a pump beam for a 500-/spl mu/m and a 100-/spl mu/m-thick undoped GaAs.