Nonlinear optical effects in strain-induced laterally ordered ${\mathrm{}\left(\mathrm{InP}\right)\mathrm{}}_2$/${\mathrm{}\left(\mathrm{GaP}\right)\mathrm{}}_2$ quantum wires

The nonlinear optical properties of a ${\mathrm{}\left(\mathrm{InP}\right)\mathrm{}}_2$/${\mathrm{}\left(\mathrm{GaP}\right)\mathrm{}}_2$ bilayer superlattice structure have been examined with linearly polarized cathodoluminescence spectroscopy. Transmission electron microscopy showed a composition modulation with a period of ∼800 Å along the [110] direction, which occurs spontaneously during the growth, resulting in coherently strained quantum wires. The strong excitation dependence of the polarization anisotropy and energy of excitonic luminescence from the quantum wires was found to be consistent with a band-filling model that is based on a k·p and two-dimensional quantum confinement calculation.