Optical coherent control in semiconductors: Fringe contrast and inhomogeneous broadening

Optical coherent control experiments in semiconductors reveal how inhomogeneous broadening must be taken into account in contrast to previous coherent control experiments in atomic and molecular systems. With spectral resolution of the coherent control signal, the optical phases involved in the interplay between the homogeneous and inhomogeneous broadenings are measured. Based on these experiments, a coherent control model describing the optical fringe contrast using different detection schemes, such as photoluminescence or four-wave mixing, is established. Significant spectral modulation is observed in the four-wave mixing spectra as a function of phase-delay representing coherent control in the spectral domain. The spectral phase change of this modulation provides a spectroscopic tool to analyze contributions of inhomogeneous broadening to electronic resonances in semiconductor structures.