Free carrier absorption in cascade structures due to static scatterers in the in-plane polarization

We report on the computation of the free carrier absorption induced by static scatterers in cascade structures when the electromagnetic wave propagates along the growth axis. We find that a Drude-like tail exists for this polarization. The absorption is found larger than when the wave propagates in the layer plane. Also intra-subband scattering is found more efficient than inter-subband scattering. The alloy scattering is found to be particularly efficient.