InP quantum dot lasers with temperature insensitive operating wavelength

摘要

We quantify the mechanisms that govern the lasing wavelength in edge-emitting InP/AlGaInP quantum dot (QD) lasers, by characterising the constituent factors controlling the temperature dependence of the gain peak wavelength. We show that a regime exists where the temperature coefficient of the bandgap can be compensated by the increasing wavelength-shift associated with state-filling in the QD ensemble, necessary to recover the gain peak magnitude. We demonstrate cleaved-facet edge-emitting lasers with a wavelength temperature dependence of 0.03 nm/K, similar to the temperature dependence of a Bragg stack fabricated in this material and approximately a sixth of the dependence of the bandgap.