Investigations of giant 'forbidden' optical anisotropy in GaInAs-InP quantum well structures

We report the unexpected observation of a large polarization anisotropy of the optical absorption for light propagating parallel to the growth axis of InGaAs-InP multi-quantum well structures. This effect, which is forbidden in the classical envelope function theory, is associated with the reduced overall symmetry of heterostructures where the host materials have no common atom: the breakdown of the fourfold rota-inversion symmetry for interface atoms leads to a non-local coupling of the heavy- and light-hole states, responsible for the optical anisotropy. The experimental results are compared with tight-binding calculations of the optical properties.