Internal stress and degradation in short-wavelength AlGaAs double heterojunction devices

Aging tests of incoherently operated zinc-doped double-heterojunction(d.h.) lasers designed for short-wavelength (0.71¿0.72 ¿m) operation show that the introduction of buffer layers between the substrate and the d.h. structure leads to a drastic reduction in gradual degradation. This is attributed to a decrease in lattice mismatch stress.