Lasing from InGaAs/GaAs quantum dots with extended wavelength and well-defined harmonic-oscillator energy levels

Data are presented on the lasing transitions from InGaAs/GaAs quantum dots that exhibit four well-resolved energy transitions, with the electronic sta te density of a two- dimensional harmonic oscillator. Lasing has been obtai ned on the second and third transitions, depending on the cavity (gain) len gth, with the longest lasing wavelength measured to be 1.19 mu m. The tempe rature dependence of threshold is studied and regions of nearly temperature -independent threshold are found. Interesting aspects of the unique electro nic state density for lasers are discussed. (C) 1998 American Institute of Physics. [S0003-6951(98)03749-8].