Abstract

The heavy hole exciton absorption resonance in a quantum well can be bleached by the presence of an exciton gas or free carrier plasma. Phase space filling (PSF) results from the blocking of transitions that would otherwise create excitons when the band states associated with the excitons are occupied. Exciton creation is only blocked by excitons or free earners of the same spin. Coulomb screening on the other hand has no dependence on the spins of particles involved when the Boltzmann approximation applies. Excess free earners also cause a collisional broadening which lowers the absorption at the peak of the absorption curve leaving the integrated oscillator strength unchanged.

© 1998 IEEE