Analysis of the reduced thermal conductivity in InGaAs/GaAsInGaAs∕GaAs quantum dot lasers from chirp characteristics

Abstract

The thermal conductivity of self-organized quantum dot (QD) active regions is estimated by measurements of wavelength chirp with injected current as a function of the current pulse duty cycle both below and above threshold. A simple model which separates out thermal and charge carrier chirps is used to estimate the thermal conductivity of the QD active region. With this model, the thermal conductivity of the InGaAs QD active region is estimated to be ∼ 0.1 W/m K∼0.1W∕mK, about two orders of magnitude less than that of the bulk material. This is consistent with theoretical predictions of the reduced thermal conductivity of QD regions.