Origin of Acoustoelectric Flux Domains in Conducting CdS

Abstract

Brillouin‐scattering measurements show that in homogeneous CdS samples, propagating flux domains originate solely from the shock produced at the cathode boundary by the pulse onset. If the shock is properly suppressed, no domains are formed, the spatial and frequency distribution of the flux being then in complete accord with the predictions of the small‐signal theory based on amplication of the rmal background noise. The enhanced parametric downconversion observed within the domain is mainly attributed to low‐frequency shock‐excited flux which acts in this case as the stimulating signal.