Stabilization of aging-induced self-pulsations and the elimination of an initial saturable mode of degradation in (Al,Ga)As lasers by means of facet coatings

We demonstrate that half-wavelength facet coatings of Al2O3can arrest the growth of pulsations in the output-intensity of (Al,Ga)As double heterostructure lasers during cw aging in a 70°C dry nitrogen ambient while also eliminating an initial saturable mode of degradation. These concurrent effects of the coatings suggest a common origin for the aging-induced pulsations and the initial degradation and also support a recently proposed model for the origin of pulsations based upon nonradiative surface recombination.