Temperature dependence of threshold current in (GaIn)(AsP) DH lasers at 1.3 and 1.5 μm wavelength

(Galn)(AsP) oxide-insulated stripe lasers for both 1.3 and 1.5 μm wavelength, and with varied levels of Zn doping, have been studied for the effect of temperature on threshold current, spontaneous efficiency and carrier recombination time. The spontaneous efficiency was found to decrease considerably with temperature, and this accounted quantitatively in every case for the observed large increase in threshold with temperature. There was a break point Tb in temperature, around 200 K, above which the efficiency started to drop appreciably. Tb decreased significantly with increase in both wavelength and Zn doping. The decrease in efficiency was acompanied by a corresponding decrease in recombination time. Auger recombination is postualted to be responsible for both effects. One anomalous wafer showed a particularly large recombination time. The p-n junction in this wafer was observed to be displaced into the upper InP layer, which probably caused the behaviour.