Degradation of GaAs lasers grown by metalorganic chemical vapor deposition on Si substrates.

Using pulsed current excitation we have studied the rapid degradation of the laser properties of low threshold graded refractive index single quantum well GaAs lasers grown by metalorganic vapor deposition on Si substrates. The degradation results from the growth of nonradiative regions in the active layer, resulting in a rapid increase in threshold with time. The stimulated emission is quenched ~1-5 microseconds after the start of the current pulse preventing continuous operation at 300K. The degradation process is similar to that observed in similar lasers grown on GaAs substrates and occurs very rapidly due to the presence of a high density of defects and thermally induced strain.