Optimization of InGaAs/GaAs quantum-well strain-layer heterojunction laser structures

Initial results are presented on the fabrication of laser diodes for the wavelength range 0.9 to 1.1 μm based on 9- and 11-layer In_xGa_1–xAs/GaAs/AlGaAs heterostructures grown by hydride-MOCVD technology. Calculations show that a prespecified wavelength (e.g., λ =0.98 μm) can be obtained over wide ranges of the compositions (0.1 ≤ x ≤ 0.4) and of the active-layer thickness (4 nm ≤ L_z ≤ 25 nm). We discuss the choice of optimal parameters as a function of the reproducibility of the growth. Emitters fabricated for λ=0.95–1.016 μm show promise for development. They exhibit no degradation under severe test conditions: at output power levels of 50 and 100 mW in the cw regime. The threshold currents I_th are 40–55 mA, and the external efficiency is ~0.2 W/A.