Answer Happy

Problem 1: Suppose that you measure the absorption spectrum of a quantum well using TM polarized light, and find the lowest exciton peak at some photon energy E₁; then you repeat the measurement with TE polarized light and find next to this peak another exciton feature at energy E2 (<E1). Explain these findings. Write an expression for E1 - E2 in terms of the well width and of the bandgap energy, dielectric constant, and effective masses of the well material. Make whatever assumption you need for an analytical expression (e.g., infinite potential barriers, 2D exciton model).