Collective free-carrier scattering in semiconductors - art. no. 165208

We present an analysis of an undoped semiconductor strongly pumped by a coh erent electromagnetic radiation held. The free-carrier dynamics and the inc ident and scattered fields are described classically and self-consistently. The analysis predicts the existence of a collective instability which simu ltaneously generates a strong free-carrier grating along the propagation di rection and a coherently backscattered radiation field. An example is given showing scattered intensities approaching 100% of the pump intensity. A re alistic experiment to enable observation of this phenomenon is described.