Temperature dependent linewidth rebroadening in quantum dot semiconductor lasers

We experimentally and analytically investigate the influence of temperature on the linewidth of an InP quantum dot (QD) laser. The full width half maximum of the peak in the optical spectrum strongly depends on the pump current and rebroadens at high injection levels. We show that with increasing temperature these effects are amplified. Applying a QD laser model including the excited and ground state with detailed balance scattering rates, we are capable of reproducing the experimentally observed data qualitatively and thus show that a relatively simple QD-laser model is capable of capturing this complex behavior. Additionally, we include a temperature dependent energy band gap reduction needed to fit the data and show that this effect enhances the rebroadening effect for higher temperatures.