Enhancement of output intensity limit of semiconductor lasers by chemical passivation of mirror facets

Reported is chemical treatment of the mirror facets of semiconductor lasers used to reduce nonradiative recombination centers, thereby enhancing their peak output power capabilities. Treatment of the surface with P/sub 2/S/sub 5/-NH/sub 4/OH coupled with washing by (NH/sub 4/)/sub 2/S can more than double the output intensity limit. However, the enhancement that can be obtained on a consistent basis is lower. It is expected that the chemically treated facet will remain passivated for times up to at least two months in air. However, to avoid photochemical processes during laser operation which could degrade the chemically passivated facet, it should be covered by an appropriate protective coating soon after the chemical treatment.<>