Vertically polarized lasing and photoluminescence in a ridge quantum-wire laser

We study vertically polarized lasing and spontaneous emissions in a ridge quantum-wire (QWR) laser. In particular, we find that most of emissions with energies near the band edge are vertically polarized. We make numerical calculation of oscillator strength for optical transitions between various combinations of electron and hole states, and indeed show oscillator strength of vertically polarized transitions is stronger in our QWR structure. We find that the different effective mass of electrons and holes, especially anisotropic effective mass of holes causes different shapes of wave functions between electrons and holes, which results in larger oscillator strength of vertically polarized transition.