Self-Heating Effect on Modal Gain of 1.3-$\mu\hbox{m}$ InAs/GaAs QD Lasers With Different $\mmb{p}$ -Doping Levels

The self-heating effect in 1.3-μm InAs/GaAs quantum dot (QD) lasers with different doping levels has been investigated by comparing the characteristics of the threshold current density (
J
_th
) and modal gain measured in continuous wave and pulsed modes with the heat sink temperature ranging from 20°C to 120°C. The results show that the
p
-doping can significantly reduce the self-heating effect in QD lasers.