Intrinsic limitations of p-doped and undoped 1.3 μm InAs/GaAs quantum dot lasers

The demand for fast and temperature stable lasers emitting in the telecom wavelengths drives the research on quantum dot lasers. While low and temperature insensitive threshold current densities are expected, InAs/GaAs quantum dot lasers emitting around 1.3 μm have not yet fulfilled their expectations. From the literature, one can observe that although high temperature stability can be achieved, this is usually at the expense of a high threshold current. P-doped devices are anticipated to achieve higher gain and bandwidth [1]. High temperature stabilities and bandwidth have been experimentally measured [2] but, to date, there is no clear measurement of the gain of devices with temperature stable threshold currents around room temperature. In this paper, we present a comparative study of the temperature dependence of both undoped and p-doped InAs/GaAs quantum dot lasers. We investigate the temperature dependence of the different radiative and nonradiative recombination mechanisms in order to understand the behavior of the devices. The conclusions allow us to explain our gain measurements carried at various temperatures on both device types.