Simultaneous measurement of the electronic and lattice temperatures in GaAs/Al0.45Ga0.55As quantum-cascade lasers:: Influence on the optical performance

We measured the electronic and lattice temperatures in steady-state operating GaAs/AlGaAs quantum-cascade lasers, by means of microprobe band-to-band photoluminescence. Thermalized hot-electron distributions with temperatures up to 800 K are established. The comparison of our data with the analysis of the temperature dependence of device optical performances shows that the threshold current is determined by the lattice temperature. (C) 2004 American Institute of Physics.