Polarization dependence of excitonic-polariton propagation in a GaAs quantum-well waveguide. K. Ogawa, T. Katsuyama and H. Nakamura in Phys. Rev. Lett. 64:796 (1990).  What the paper says!?

This work studies the polarization dependence of «quantum-well excitonic polaritons (QWEP's)». It follows the earlier observation of such exciton-polariton propagation in a QW without focus on polarization. This text is more cited although the previous one is more important and better written.

This relies on polariton waveguides:

To propagate a laser pulse along the quantum-well layer in the time-of-flight measurements, a sample having a waveguide structure was grown by molecular-beam epitaxy on an undoped GaAs substrate.

The core is a thick 250 periods of alternating layers sandwiching a GaAs quantum well, where «QWEP's propagate as guided waves. »

They performed time-of-flight measurements and absorption, evidencing polarization effects (light and heavy holes).

This text is cited by B. Sermage et al. as «First indirect and controversial studies of the in-plane polariton transport in microcavities» (this isn't in a microcavity, and it is unclear why "controversial").