Theoretical Studies of Polarization Dependent Electro-optical Modulation in Latticis Matched and Strained Multi-quantum Well Structures

We report on polarization dependent optical absorption for excitonic and interband transitions in lattice matched (GaAs/AlGaAs) and strained (biaxial tensile strain GaAsP/AlGaAs; biaxial compressive strain InGaAs/AlGaAs) multiquantum well structures in the presence of transverse electric fields. The hole states are solved by using the Kohn-Luttinger Hamiltonian and using an eigenvalue technique. The effect of heavy-hole and light-hole mixing due to the strain, electric field and quantization is studied. Under biaxial tensile strain the heavy-hole and light-hole transition can coincide,leading to interesting polarization dependent effects. Results are presented for excitonic and interband transitions.