FEMTOSECOND SPECTRAL INTERFEROMETRY OF RESONANT SECONDARY-EMISSION FROM QUANTUM-WELLS - RESONANCE RAYLEIGH-SCATTERING IN THE NONERGODIC REGIME

We report the first investigation of resonant secondary emission from quantum well excitons using ultrafast spectral interferometry. Observa tion of high-contrast spectral fringes demonstrates a significant phas e correlation of the spectral components of the Rayleigh scattered lig ht and allows us to determine the temporal dynamics of the coherent em ission. The results contradict the present theories for resonant Rayle igh scattering based on ensemble averaging, and show the nonergodic na ture of resonance Rayleigh scattering from semiconductor quantum wells .