Stability of sulfur-passivated facets of InGaAs-AlGaAs laser diodes

The facets of GaAs-AlGaAs ridge waveguide (RW) laser diodes were passivated using (NH/sub 4/)/sub 2/S/sub x/. The effectiveness of this procedure was checked by electroluminescence power-voltage-current (P-V-I) measurements that provide information on the changes in the density of surface states. Using this nondestructive method, the degradation of the passivation under ambient atmosphere has been studied. Capping with silicon nitride is found to stabilize the sulfur passivation and avoid degradation.