Abstract

Time-resolved photon echoes allow the investigation of the dynamics of interaction processes that lead to the dephasing of electronic states in semiconducting materials. For instance, with this technique, the femtosecond polarization dephasing times due to exciton-exciton and exdton-clectron scattering¹ or carrier-carrier scattering² have been measured in bulk CaAs or in quantum well structures for exciton-exciton³ and carrier-carrier interactions.⁴ At very low carrier densities (typically below 10¹⁶ cm⁻³), the above mechanisms are less important and the dephasing is expected to be due to scattering with phonons.

© 1992 Optical Society of America