Abstract

Phase Conjugation of Nonlinear Acoustic Waves in Piezosemiconductors

A.Brysev, V.G.Mikhalevich, V.N.Streltsov (Wave Research Center of the General Physics Institute RAS, Moscow, Russia)

e-mail: brysev@orc.ru; brysev@kapella.gpi.ru

The real time acoustic waves phase conjugation (WPC), based on the self-consistent physical mechanisms, was realized up to present time only for the monochromatic waves [1]. In this report the possibility of the WPC of nonmonochromatic acoustic waves is considered. For simultaneous WPC of the whole series of the spectral components originated by the previous nonlinear propagation of the incident wave we proposed to use the phonon-plasmon interaction in piezosemiconductors. WPC of nonlinear acoustic waves in this case can be realized due to electron's density modulation provided by the train of short light impulses pumping the sample. If the light impulse train period is half of the fundamental acoustic component's period, such kind of wide-band excitation leads to the self-synchronized parametric conjugation for each spectrum component of the incident wave. The conjugation efficiency sharply depends on the relations between component frequency, light impulse duration and interband relaxation time. The time profile distortions of the conjugated wave are investigated for some physical conditions of practical interest. It is shown that under certain conditions the time profile of conjugate wave may be efficiently controlled by the variation of the pumping impulses duration. [1]. A.P. Brysev, et al. Phys.-Usp. 41 793 (1998)

Section : 10