INJECTION HETEROLASER BASED ON AN ARRAY OF VERTICALLY ALIGNED INGAAS QUANTUM DOTS IN A ALGAAS MATRIX

Arrays of vertically aligned InGaAs quantum dots in a AlGaAs matrix ha ve been investigated. It is shown that increasing the band gap of the matrix material makes it possible to increase the localization energy of quantum dots relative to the edge of the matrix band, as well as th e states of the wetting layer. The use of an injection laser as the ac tive region makes it possible to decrease the thermal filling of highe r-lying states, and thereby decrease the threshold current density to 63 A/cm(2) at room temperature. A model explaining the negative charac teristic temperature section observed at low temperatures is proposed. The model is based on the assumption that a transition occurs from no nequilibrium to equilibrium filling of the states of the quantum dots. (C) 1997 American Institute of Physics.