Abstract

The Photoexcitation of Hypersound in Ge in Presence of the Electric Field

N.Chigarev (International Laser Center, Moscow State Univerisity, Moscow, Russia); S.Strelkov, V.G.Michalevich (General Physics Institute RAN, Moscow, Russia)

e-mail: Chigarev@polys1.phys.msu.su

The photoexcitation of the hypersound pulses in semiconductors is attractive problem due to the possibility of their acceleration. Such possibility is connected with so called electron-deformation mechanism of sound excitation. Here we presented the results of researches of ultra-short sound pulse photoexcitation in crystalline Ge in the presence of stationary electric field. The time displacement of subnanosecond hypersound pulse in electric field was observed. The drift of photoexcited carriers is taken into account by means of non-equilibrium functions of their distribution. The mechanical displacement of the lattice is described by one-dementia wave equation. The solution of the equations is obtained in spectral form. It is shown that the application of electric field gives the amplification and the displacement of hypersound pulse in case if the drift velocity of eh-plasma is close to the velocity of sound. The correlations between the experiment and the theory are discussed.

Section : 9