Unified picture of polariton propagation in bulk GaAs semiconductors

High-resolution amplitude and phase linear spectroscopy of high-quality bulk GaAs are reported. The detailed structure of the observed full complex transmission is consistently explained by polariton effects on the basis of microscopic calculations. The coupled equations for the excitonic polarization and the light field in the slab configuration are evaluated using appropriate boundary conditions for the electro-magnetic field and the excitonic wave function without reference to additional boundary conditions For the macroscopic polarization.