Fermi-dirac and random carrier distributions in quantum dot lasers

Using experimental gain and emission measurements as functions of temperature, a method is described to characterise the carrier distribution of radiative states in a quantum dot (QD) laser structure in terms of a temperature. This method is independent of the form of the inhomogeneous dot distribution. A thermal distribution at the lattice temperature is found between 200 and 300K. Below 200K the characteristic temperature exceeds the lattice temperature and the distribution becomes random below about 60 K. This enables the temperature range for which Fermi-Dirac statistics are applicable in QD laser threshold calculations to be identified. (C) 2014 AIP Publishing LLC