High performance quantum dot lasers on GaAs substrates operating in 1.5 µm range

Stacked InAs/InGaAs quantum dots are used as an active media of metamorphic InGaAs–InGaAlAs lasers grown on GaAs substrates by molecular beam epitaxy. High quantum efficiency (ηi>60%) and low internal losses (α<3–4 cm−1) are realised. The transparency current density per single QD layer is estimated as ∼70 A/cm2 and the characteristic temperature is 60 K (20–85°C). The emission wavelength exceeds 1.51 µm at temperatures above 60°C.