Gain spectra of quantum wires with inhomogeneous broadening
The effects of fabricational variations on the gain spectra of quantum wires are calculated within the limits of first-order perturbation theory. Gain spectra and density of states for 50-Å-radius and 150-Å-radius cylindrical quantum wires are calculated and plotted for several different fabrication tolerances. The wave functions for a finite, cylindrical potential are calculated and a quasicritical radius, below which the carriers are weakly confined by the potential, is established. This sets a lower limit on quantum wire size. Upper limits on the size of quantum wells, quantum wires, and quantum boxes are also discussed. The threshold current and differential gain of quantum-wire lasers and quantum wire array lasers are calculated. These calculations indicate a possible reduction in threshold current of one to two orders of magnitude as compared to the best quantum-well lasers.