Reproducible Liquid-Phase-Epitaxial Growth of Double Heterostructure GaAs–AlxGa1−xAs Laser Diodes

Highly uniform GaAs–AlxGa1−xAs double heterostructure (DH) wafers have been reproducibly grown, and when fabricated into DH laser diodes yield diodes whose current threshold densities Jth lie within ±5% of each other. Other laser parameters such as lasing wavelength and external differential quantum efficiency ηD also show the same uniformity. The DH wafers can be reproducibly grown so that these parameters lie within ±10% from wafer to wafer. The methods used to achieve these results employ a well-designed sample holder, minimization of contaminants into the system, reproduction of oven gradients from run to run, and careful temperature control and temperature reproducibility. Using these techniques, we have been able to grow DH wafers, whose active layers are as thin as 0.14 μm. When fabricated into laser diodes, 200 mW of continuous power output has been obtained at room temperature.