Excitation and suppression of coherent LO-phonon-plasmon oscillations in GaAs by two ultrashort laser pulses

Summary form only given. Recently, the dynamics of photoexcited coherent plasmon-phonon modes in GaAs has been investigated by a time-domain spectroscopy. We extend the theory of coherent plasmon-phonon photoexcitation in several ways. First, the use of Laplace transform technique allowed us to obtain a simple analytical solution for the equations for coupled plasmon-phonon modes. These equations were solved either in the perturbative regime or numerically. Second, we studied the effect of a second laser pulse on the coherent dynamics of plasmon-phonon modes excited by the first pulse. The effect that we found opens the possibility to control the coherent plasmon-phonon excitations by ultrashort laser pulses.