Abstract

Currently, transient optical phenomena in semiconductors are attracting considerable interest both theoretically [1-2] and experimentally [3-4] in connection with recent advances in ultra short-pulse spectroscopy. The relaxation into quasi-equilibrium of a dense electron-hole plasma in a semiconductor previously excited by a strong femtosecond optical pulse is determined by the carrier-scattering processes and lies in femtosecond time scale (τ_s typically 20 fs - 500 fs). In fact the carrier-scattering processes are determined both by the Coulomb mechanism which conserves the total momentum of the electron-hole system and dominates at high plasma densities and by carrier interaction with any crystal imperfections, i.e. phonons or impurities.

© 1992 The Author(s)