Normal incidence GaAs/AlGaAs multiple-quantum-well polarization modulator using an induced uniaxial strain

Summary form only given. A demonstration of a novel polarization modulator with light incident normal to the surface of the modulator is reported. The layered pattern in a multiple quantum well (MQW) breaks the full cubic symmetry of the host materials. These structures, though, reserve a fourfold rotation symmetry about the growth axis normal to (100) oriented substrates. A uniaxial stress applied in the plane of the structure further reduces this rotation symmetry, mixing the heavy and light hole bands and creating an anisotropy in the in-plane components of the dielectric function, thus allowing the use of this device as a polarization modulator with a contrast ratio ~55:1 with a 5 V applied bias. A p-i-n structure grown on (100) GaAs was used for the modulator. The intrinsic region consists of a 100-period, 150-Å GaAs/50-Å Al_0.1Ga_0.9As MQW