Nonequilibrium distribution in quantum dots lasers and influence on laser spectral output

Self-assembled quantum dot structures used for lasers have shown significant variation in the dot size distribution. In this article, we address the issues related to carrier occupation of these dots as a function of temperature in the absence and presence of lasing. The carrier distributions among different dots are derived in this paper through detailed balance. It is found that at low temperatures the carrier occupation is highly nonequilibrium but with increased temperature it tends towards an equilibrium distribution. Based on this distribution, the threshold current density versus temperature has been calculated. Multimode operation of lasers at different injection levels and temperatures is also examined. The theoretical results are compared with published experimental results. (C) 1999 American Institute of Physics. [S0021-8979(99)03210-7].