Controlling polarization of quantum-dot surface-emitting lasers by using structurally anisotropic self-assembled quantum dots

Abstract

Polarization control is achieved in vertical-cavity surface-emitting lasers (VCSELs) by using structurally anisotropic self-assembled quantum dots (QDs) as active layers. The dot shape is long in the [01̄1] direction on the (100) surface. The photoluminescence from the dots has a polarization dependence whose intensity along the [01̄1] direction is 1.37 times stronger than that along the orthogonal [011] direction. The QD VCSEL operates at the wavelength of the QD ground state transition. Lasing emission shows polarization along the [01̄1] direction and an orthogonal polarization suppression ratio of 18 dB.