Model of the Excitonic Surface Layer in Normal Incidence Reflection

A pair of semiclassical wave equations describing exciton polaritons of Wannier type is set up and solved for half‐space geometry under certain simplifying assumptions. The main results are: (i) the polarization as a function of the distance from the boundary; (ii) an energy dependence of the depth of the transition region; (iii) evidence for a possibly non‐monotonous behaviour of the polarization near the boundary if the frequency is above resonance; (iv) reflection curves that for certain parameter sets give spikes for ω > ωL.