This chapter discusses the coherent nonlinear pulse propagation. It identifies coherent exciton light coupling over a broad intensity range and permits comparison with numerical calculations based on the semiconductor Maxwell-Bloch equations. At low light intensities, polariton propagation beats owing to the interference between excited states on both polariton branches. In an intermediate intensity regime, the temporal polariton beating is suppressed in consequence of exciton-exciton interaction. At the highest light intensities, self-induced transmission and multiple pulse breakup are identified as a signature for carrier density Rabi flopping. Exciton-phonon scattering is shown to gradually eliminate coherent nonlinear propagation effects due to enhanced dephasing of the excitonic polarization. The experiments can be described theoretically using the semiconductor Maxwell-Bloch equations, which accomplish the transition from linear to nonlinear optics by taking into account many-body interactions consisting of mean-field and correlation effects. The chapter, in addition, discusses the intensity to pulse area relation, pulse delays, and effective propagation velocities in dependence on the pulse intensity yield quantitative agreement between the experiment and the semiconductor Maxwell-Bloch theory.
ASJC Scopus subject areas
- Physics and Astronomy(all)