Ultrahigh gain and non-radiative recombination channels in 1.5 mu m range metamorphic InAs-InGaAs quantum dot lasers on GaAs substrates

摘要

Metamorphic InAs-InGaAs quantum dot (QD) lasers grown on GaAs substrates by molecular beam epitaxy have been studied. The lasing wavelength of about 1.5 mum and the threshold current density of 1650 A cm(-2) for a 2 mm cavity laser diode have been observed. The characteristic temperature of 66 K has been shown in the temperature range from 30 to 80 degreesC. The analysis of spontaneous emission efficiency corroborates the high contribution of non-radiative recombination in the total recombination current, even at high current densities. The possibility of achieving modal gain as high as 190 cm(-1) has been demonstrated.