Absorption anisotropy for lattice matched GaAs/AlGaAs multiple quantum well structures under external anisotropic biaxial strain: Compression along [110] and tension along [(1)over-bar10]

We report theoretical studies on the optical absorption anisotropy for excitonic transitions in lattice-matched GaAs/AlGaAs multiple quantum well (MQW) structures under simultaneous compression and tension applied along the [110] and [(1) over bar 10] directions of the MQW, respectively. The analyses are based on a model that includes both the 4 x 4 k.p Hamiltonian and the strain Hamiltonian. The wave functions, found by solving the eigenvalue equations, are used to calculate the dipole matrix elements for excitonic transitions and evaluate the anisotropic absorption properties. The effect of variation of parameters such as well width and barrier height on the performance of the strained GaAs/AlGaAs MQW electroabsorption modulators is discussed.